:: RLAFFIN1 semantic presentation begin registration let RLS be non empty RLSStruct ; let A be empty Subset of RLS; cluster conv A -> empty ; coherence conv A is empty proof A = the empty convex Subset of RLS ; then A in Convex-Family A by CONVEX1:def_4; hence conv A is empty by SETFAM_1:4; ::_thesis: verum end; end; Lm1: for RLS being non empty RLSStruct for A being Subset of RLS holds A c= conv A proof let RLS be non empty RLSStruct ; ::_thesis: for A being Subset of RLS holds A c= conv A let A be Subset of RLS; ::_thesis: A c= conv A let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in A or x in conv A ) assume A1: x in A ; ::_thesis: x in conv A A2: now__::_thesis:_for_y_being_set_st_y_in_Convex-Family_A_holds_ x_in_y let y be set ; ::_thesis: ( y in Convex-Family A implies x in y ) assume y in Convex-Family A ; ::_thesis: x in y then A c= y by CONVEX1:def_4; hence x in y by A1; ::_thesis: verum end; [#] RLS is convex by CONVEX1:16, RUSUB_4:22; then [#] RLS in Convex-Family A by CONVEX1:def_4; hence x in conv A by A2, SETFAM_1:def_1; ::_thesis: verum end; registration let RLS be non empty RLSStruct ; let A be non empty Subset of RLS; cluster conv A -> non empty ; coherence not conv A is empty proof A c= conv A by Lm1; hence not conv A is empty ; ::_thesis: verum end; end; theorem :: RLAFFIN1:1 for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for v being Element of R holds conv {v} = {v} proof let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: for v being Element of R holds conv {v} = {v} let v be Element of R; ::_thesis: conv {v} = {v} {v} is convex proof let u1, u2 be VECTOR of R; :: according to CONVEX1:def_2 ::_thesis: for b1 being Element of REAL holds ( b1 <= 0 or 1 <= b1 or not u1 in {v} or not u2 in {v} or (b1 * u1) + ((1 - b1) * u2) in {v} ) let r be Real; ::_thesis: ( r <= 0 or 1 <= r or not u1 in {v} or not u2 in {v} or (r * u1) + ((1 - r) * u2) in {v} ) assume that 0 < r and r < 1 ; ::_thesis: ( not u1 in {v} or not u2 in {v} or (r * u1) + ((1 - r) * u2) in {v} ) assume that A1: u1 in {v} and A2: u2 in {v} ; ::_thesis: (r * u1) + ((1 - r) * u2) in {v} ( u1 = v & u2 = v ) by A1, A2, TARSKI:def_1; then (r * u1) + ((1 - r) * u2) = (r + (1 - r)) * u1 by RLVECT_1:def_6 .= u1 by RLVECT_1:def_8 ; hence (r * u1) + ((1 - r) * u2) in {v} by A1; ::_thesis: verum end; then conv {v} c= {v} by CONVEX1:30; hence conv {v} = {v} by ZFMISC_1:33; ::_thesis: verum end; theorem :: RLAFFIN1:2 for RLS being non empty RLSStruct for A being Subset of RLS holds A c= conv A by Lm1; theorem Th3: :: RLAFFIN1:3 for RLS being non empty RLSStruct for A, B being Subset of RLS st A c= B holds conv A c= conv B proof let RLS be non empty RLSStruct ; ::_thesis: for A, B being Subset of RLS st A c= B holds conv A c= conv B let A, B be Subset of RLS; ::_thesis: ( A c= B implies conv A c= conv B ) assume A1: A c= B ; ::_thesis: conv A c= conv B A2: Convex-Family B c= Convex-Family A proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Convex-Family B or x in Convex-Family A ) assume A3: x in Convex-Family B ; ::_thesis: x in Convex-Family A then reconsider X = x as Subset of RLS ; B c= X by A3, CONVEX1:def_4; then A4: A c= X by A1, XBOOLE_1:1; X is convex by A3, CONVEX1:def_4; hence x in Convex-Family A by A4, CONVEX1:def_4; ::_thesis: verum end; [#] RLS is convex by CONVEX1:16, RUSUB_4:22; then [#] RLS in Convex-Family B by CONVEX1:def_4; then A5: meet (Convex-Family A) c= meet (Convex-Family B) by A2, SETFAM_1:6; let y be set ; :: according to TARSKI:def_3 ::_thesis: ( not y in conv A or y in conv B ) assume y in conv A ; ::_thesis: y in conv B hence y in conv B by A5; ::_thesis: verum end; theorem :: RLAFFIN1:4 for RLS being non empty RLSStruct for S, A being Subset of RLS st A c= conv S holds conv S = conv (S \/ A) proof let RLS be non empty RLSStruct ; ::_thesis: for S, A being Subset of RLS st A c= conv S holds conv S = conv (S \/ A) let S, A be Subset of RLS; ::_thesis: ( A c= conv S implies conv S = conv (S \/ A) ) assume A1: A c= conv S ; ::_thesis: conv S = conv (S \/ A) thus conv S c= conv (S \/ A) by Th3, XBOOLE_1:7; :: according to XBOOLE_0:def_10 ::_thesis: conv (S \/ A) c= conv S S c= conv S by Lm1; then S \/ A c= conv S by A1, XBOOLE_1:8; hence conv (S \/ A) c= conv S by CONVEX1:30; ::_thesis: verum end; Lm2: for V being non empty right_complementable add-associative right_zeroed addLoopStr for A, B being Subset of V for v being Element of V holds (v + A) \ (v + B) = v + (A \ B) proof let V be non empty right_complementable add-associative right_zeroed addLoopStr ; ::_thesis: for A, B being Subset of V for v being Element of V holds (v + A) \ (v + B) = v + (A \ B) let A, B be Subset of V; ::_thesis: for v being Element of V holds (v + A) \ (v + B) = v + (A \ B) let v be Element of V; ::_thesis: (v + A) \ (v + B) = v + (A \ B) hereby :: according to TARSKI:def_3,XBOOLE_0:def_10 ::_thesis: v + (A \ B) c= (v + A) \ (v + B) let x be set ; ::_thesis: ( x in (v + A) \ (v + B) implies x in v + (A \ B) ) assume A1: x in (v + A) \ (v + B) ; ::_thesis: x in v + (A \ B) then x in v + A by XBOOLE_0:def_5; then consider w being Element of V such that A2: x = v + w and A3: w in A ; not x in v + B by A1, XBOOLE_0:def_5; then not w in B by A2; then w in A \ B by A3, XBOOLE_0:def_5; hence x in v + (A \ B) by A2; ::_thesis: verum end; let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in v + (A \ B) or x in (v + A) \ (v + B) ) assume x in v + (A \ B) ; ::_thesis: x in (v + A) \ (v + B) then consider w being Element of V such that A4: x = v + w and A5: w in A \ B ; A6: not x in v + B proof assume x in v + B ; ::_thesis: contradiction then consider s being Element of V such that A7: x = v + s and A8: s in B ; s = w by A4, A7, RLVECT_1:8; hence contradiction by A5, A8, XBOOLE_0:def_5; ::_thesis: verum end; w in A by A5, XBOOLE_0:def_5; then x in v + A by A4; hence x in (v + A) \ (v + B) by A6, XBOOLE_0:def_5; ::_thesis: verum end; Lm3: for S being non empty addLoopStr for v, w being Element of S holds {(v + w)} = v + {w} proof let S be non empty addLoopStr ; ::_thesis: for v, w being Element of S holds {(v + w)} = v + {w} let p, q be Element of S; ::_thesis: {(p + q)} = p + {q} hereby :: according to TARSKI:def_3,XBOOLE_0:def_10 ::_thesis: p + {q} c= {(p + q)} let x be set ; ::_thesis: ( x in {(p + q)} implies x in p + {q} ) assume x in {(p + q)} ; ::_thesis: x in p + {q} then A1: x = p + q by TARSKI:def_1; q in {q} by TARSKI:def_1; hence x in p + {q} by A1; ::_thesis: verum end; let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in p + {q} or x in {(p + q)} ) assume x in p + {q} ; ::_thesis: x in {(p + q)} then consider v being Element of S such that A2: x = p + v and A3: v in {q} ; v = q by A3, TARSKI:def_1; hence x in {(p + q)} by A2, TARSKI:def_1; ::_thesis: verum end; theorem Th5: :: RLAFFIN1:5 for V being non empty add-associative addLoopStr for A being Subset of V for v, w being Element of V holds (v + w) + A = v + (w + A) proof let V be non empty add-associative addLoopStr ; ::_thesis: for A being Subset of V for v, w being Element of V holds (v + w) + A = v + (w + A) let A be Subset of V; ::_thesis: for v, w being Element of V holds (v + w) + A = v + (w + A) let v, w be Element of V; ::_thesis: (v + w) + A = v + (w + A) set vw = v + w; thus (v + w) + A c= v + (w + A) :: according to XBOOLE_0:def_10 ::_thesis: v + (w + A) c= (v + w) + A proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in (v + w) + A or x in v + (w + A) ) assume x in (v + w) + A ; ::_thesis: x in v + (w + A) then consider s being Element of V such that A1: ( x = (v + w) + s & s in A ) ; ( w + s in w + A & x = v + (w + s) ) by A1, RLVECT_1:def_3; hence x in v + (w + A) ; ::_thesis: verum end; let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in v + (w + A) or x in (v + w) + A ) assume x in v + (w + A) ; ::_thesis: x in (v + w) + A then consider s being Element of V such that A2: x = v + s and A3: s in w + A ; consider r being Element of V such that A4: s = w + r and A5: r in A by A3; x = (v + w) + r by A2, A4, RLVECT_1:def_3; hence x in (v + w) + A by A5; ::_thesis: verum end; theorem Th6: :: RLAFFIN1:6 for V being non empty Abelian right_zeroed addLoopStr for A being Subset of V holds (0. V) + A = A proof let V be non empty Abelian right_zeroed addLoopStr ; ::_thesis: for A being Subset of V holds (0. V) + A = A let A be Subset of V; ::_thesis: (0. V) + A = A thus (0. V) + A c= A :: according to XBOOLE_0:def_10 ::_thesis: A c= (0. V) + A proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in (0. V) + A or x in A ) assume x in (0. V) + A ; ::_thesis: x in A then ex s being Element of V st ( x = (0. V) + s & s in A ) ; hence x in A by RLVECT_1:def_4; ::_thesis: verum end; let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in A or x in (0. V) + A ) assume A1: x in A ; ::_thesis: x in (0. V) + A then reconsider v = x as Element of V ; (0. V) + v = v by RLVECT_1:def_4; hence x in (0. V) + A by A1; ::_thesis: verum end; Lm4: for V being non empty addLoopStr for A being Subset of V for v being Element of V holds card (v + A) c= card A proof let V be non empty addLoopStr ; ::_thesis: for A being Subset of V for v being Element of V holds card (v + A) c= card A let A be Subset of V; ::_thesis: for v being Element of V holds card (v + A) c= card A let v be Element of V; ::_thesis: card (v + A) c= card A deffunc H1( Element of V) -> Element of the carrier of V = v + $1; card { H1(w) where w is Element of V : w in A } c= card A from TREES_2:sch_2(); hence card (v + A) c= card A ; ::_thesis: verum end; theorem Th7: :: RLAFFIN1:7 for G being non empty right_complementable Abelian add-associative right_zeroed addLoopStr for g being Element of G for A being Subset of G holds card A = card (g + A) proof let G be non empty right_complementable Abelian add-associative right_zeroed addLoopStr ; ::_thesis: for g being Element of G for A being Subset of G holds card A = card (g + A) let g be Element of G; ::_thesis: for A being Subset of G holds card A = card (g + A) let A be Subset of G; ::_thesis: card A = card (g + A) (- g) + (g + A) = ((- g) + g) + A by Th5 .= (0. G) + A by RLVECT_1:5 .= A by Th6 ; then A1: card A c= card (g + A) by Lm4; card (g + A) c= card A by Lm4; hence card A = card (g + A) by A1, XBOOLE_0:def_10; ::_thesis: verum end; theorem Th8: :: RLAFFIN1:8 for S being non empty addLoopStr for v being Element of S holds v + ({} S) = {} S proof let S be non empty addLoopStr ; ::_thesis: for v being Element of S holds v + ({} S) = {} S let v be Element of S; ::_thesis: v + ({} S) = {} S assume v + ({} S) <> {} S ; ::_thesis: contradiction then consider x being set such that A1: x in v + ({} S) by XBOOLE_0:def_1; ex w being Element of S st ( x = v + w & w in {} S ) by A1; hence contradiction ; ::_thesis: verum end; theorem Th9: :: RLAFFIN1:9 for r being Real for RLS being non empty RLSStruct for A, B being Subset of RLS st A c= B holds r * A c= r * B proof let r be Real; ::_thesis: for RLS being non empty RLSStruct for A, B being Subset of RLS st A c= B holds r * A c= r * B let RLS be non empty RLSStruct ; ::_thesis: for A, B being Subset of RLS st A c= B holds r * A c= r * B let A, B be Subset of RLS; ::_thesis: ( A c= B implies r * A c= r * B ) assume A1: A c= B ; ::_thesis: r * A c= r * B let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in r * A or x in r * B ) assume x in r * A ; ::_thesis: x in r * B then ex v being Element of RLS st ( x = r * v & v in A ) ; hence x in r * B by A1; ::_thesis: verum end; theorem Th10: :: RLAFFIN1:10 for r, s being Real for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for AR being Subset of R holds (r * s) * AR = r * (s * AR) proof let r, s be Real; ::_thesis: for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for AR being Subset of R holds (r * s) * AR = r * (s * AR) let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: for AR being Subset of R holds (r * s) * AR = r * (s * AR) let AR be Subset of R; ::_thesis: (r * s) * AR = r * (s * AR) set rs = r * s; hereby :: according to TARSKI:def_3,XBOOLE_0:def_10 ::_thesis: r * (s * AR) c= (r * s) * AR let x be set ; ::_thesis: ( x in (r * s) * AR implies x in r * (s * AR) ) assume x in (r * s) * AR ; ::_thesis: x in r * (s * AR) then consider v being Element of R such that A1: ( x = (r * s) * v & v in AR ) ; ( s * v in s * AR & x = r * (s * v) ) by A1, RLVECT_1:def_7; hence x in r * (s * AR) ; ::_thesis: verum end; let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in r * (s * AR) or x in (r * s) * AR ) assume x in r * (s * AR) ; ::_thesis: x in (r * s) * AR then consider v being Element of R such that A2: x = r * v and A3: v in s * AR ; consider w being Element of R such that A4: v = s * w and A5: w in AR by A3; (r * s) * w = x by A2, A4, RLVECT_1:def_7; hence x in (r * s) * AR by A5; ::_thesis: verum end; theorem Th11: :: RLAFFIN1:11 for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for AR being Subset of R holds 1 * AR = AR proof let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: for AR being Subset of R holds 1 * AR = AR let AR be Subset of R; ::_thesis: 1 * AR = AR hereby :: according to TARSKI:def_3,XBOOLE_0:def_10 ::_thesis: AR c= 1 * AR let x be set ; ::_thesis: ( x in 1 * AR implies x in AR ) assume x in 1 * AR ; ::_thesis: x in AR then ex v being Element of R st ( x = 1 * v & v in AR ) ; hence x in AR by RLVECT_1:def_8; ::_thesis: verum end; let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in AR or x in 1 * AR ) assume A1: x in AR ; ::_thesis: x in 1 * AR reconsider v = x as Element of R by A1; x = 1 * v by RLVECT_1:def_8; hence x in 1 * AR by A1; ::_thesis: verum end; theorem Th12: :: RLAFFIN1:12 for V being RealLinearSpace for A being Subset of V holds 0 * A c= {(0. V)} proof let V be RealLinearSpace; ::_thesis: for A being Subset of V holds 0 * A c= {(0. V)} let A be Subset of V; ::_thesis: 0 * A c= {(0. V)} let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in 0 * A or x in {(0. V)} ) assume x in 0 * A ; ::_thesis: x in {(0. V)} then ex v being Element of V st ( x = 0 * v & v in A ) ; then x = 0. V by RLVECT_1:10; hence x in {(0. V)} by TARSKI:def_1; ::_thesis: verum end; theorem Th13: :: RLAFFIN1:13 for S being non empty addLoopStr for LS1, LS2 being Linear_Combination of S for F being FinSequence of S holds (LS1 + LS2) * F = (LS1 * F) + (LS2 * F) proof let S be non empty addLoopStr ; ::_thesis: for LS1, LS2 being Linear_Combination of S for F being FinSequence of S holds (LS1 + LS2) * F = (LS1 * F) + (LS2 * F) let LS1, LS2 be Linear_Combination of S; ::_thesis: for F being FinSequence of S holds (LS1 + LS2) * F = (LS1 * F) + (LS2 * F) let p be FinSequence of S; ::_thesis: (LS1 + LS2) * p = (LS1 * p) + (LS2 * p) A1: len (LS1 * p) = len p by FINSEQ_2:33; A2: len (LS2 * p) = len p by FINSEQ_2:33; then reconsider L1p = LS1 * p, L2p = LS2 * p as Element of (len p) -tuples_on REAL by A1, FINSEQ_2:92; A3: len ((LS1 + LS2) * p) = len p by FINSEQ_2:33; A4: now__::_thesis:_for_k_being_Nat_st_1_<=_k_&_k_<=_len_p_holds_ ((LS1_+_LS2)_*_p)_._k_=_(L1p_+_L2p)_._k let k be Nat; ::_thesis: ( 1 <= k & k <= len p implies ((LS1 + LS2) * p) . k = (L1p + L2p) . k ) assume A5: ( 1 <= k & k <= len p ) ; ::_thesis: ((LS1 + LS2) * p) . k = (L1p + L2p) . k then k in dom ((LS1 + LS2) * p) by A3, FINSEQ_3:25; then A6: ((LS1 + LS2) * p) . k = (LS1 + LS2) . (p . k) by FUNCT_1:12; k in dom L1p by A1, A5, FINSEQ_3:25; then A7: ( p . k in dom LS1 & L1p . k = LS1 . (p . k) ) by FUNCT_1:11, FUNCT_1:12; k in dom L2p by A2, A5, FINSEQ_3:25; then A8: L2p . k = LS2 . (p . k) by FUNCT_1:12; dom LS1 = the carrier of S by FUNCT_2:def_1; hence ((LS1 + LS2) * p) . k = (L1p . k) + (L2p . k) by A6, A8, A7, RLVECT_2:def_10 .= (L1p + L2p) . k by RVSUM_1:11 ; ::_thesis: verum end; len (L1p + L2p) = len p by CARD_1:def_7; hence (LS1 + LS2) * p = (LS1 * p) + (LS2 * p) by A3, A4, FINSEQ_1:14; ::_thesis: verum end; theorem Th14: :: RLAFFIN1:14 for r being Real for V being RealLinearSpace for L being Linear_Combination of V for F being FinSequence of V holds (r * L) * F = r * (L * F) proof let r be Real; ::_thesis: for V being RealLinearSpace for L being Linear_Combination of V for F being FinSequence of V holds (r * L) * F = r * (L * F) let V be RealLinearSpace; ::_thesis: for L being Linear_Combination of V for F being FinSequence of V holds (r * L) * F = r * (L * F) let L be Linear_Combination of V; ::_thesis: for F being FinSequence of V holds (r * L) * F = r * (L * F) let p be FinSequence of V; ::_thesis: (r * L) * p = r * (L * p) A1: len ((r * L) * p) = len p by FINSEQ_2:33; A2: len (L * p) = len p by FINSEQ_2:33; then reconsider rLp = (r * L) * p, Lp = L * p as Element of (len p) -tuples_on REAL by A1, FINSEQ_2:92; A3: now__::_thesis:_for_k_being_Nat_st_1_<=_k_&_k_<=_len_p_holds_ rLp_._k_=_(r_*_Lp)_._k let k be Nat; ::_thesis: ( 1 <= k & k <= len p implies rLp . k = (r * Lp) . k ) assume A4: ( 1 <= k & k <= len p ) ; ::_thesis: rLp . k = (r * Lp) . k then k in dom Lp by A2, FINSEQ_3:25; then A5: ( Lp . k = L . (p . k) & p . k in dom L ) by FUNCT_1:11, FUNCT_1:12; k in dom rLp by A1, A4, FINSEQ_3:25; then A6: rLp . k = (r * L) . (p . k) by FUNCT_1:12; ( (r * Lp) . k = r * (Lp . k) & dom L = the carrier of V ) by FUNCT_2:def_1, RVSUM_1:44; hence rLp . k = (r * Lp) . k by A5, A6, RLVECT_2:def_11; ::_thesis: verum end; len (r * Lp) = len p by CARD_1:def_7; hence (r * L) * p = r * (L * p) by A1, A3, FINSEQ_1:14; ::_thesis: verum end; theorem Th15: :: RLAFFIN1:15 for V being RealLinearSpace for A, B being Subset of V st A is linearly-independent & A c= B & Lin B = V holds ex I being linearly-independent Subset of V st ( A c= I & I c= B & Lin I = V ) proof let V be RealLinearSpace; ::_thesis: for A, B being Subset of V st A is linearly-independent & A c= B & Lin B = V holds ex I being linearly-independent Subset of V st ( A c= I & I c= B & Lin I = V ) let A, B be Subset of V; ::_thesis: ( A is linearly-independent & A c= B & Lin B = V implies ex I being linearly-independent Subset of V st ( A c= I & I c= B & Lin I = V ) ) assume that A1: ( A is linearly-independent & A c= B ) and A2: Lin B = V ; ::_thesis: ex I being linearly-independent Subset of V st ( A c= I & I c= B & Lin I = V ) defpred S1[ set ] means ex I being Subset of V st ( I = $1 & A c= I & I c= B & I is linearly-independent ); consider Q being set such that A3: for Z being set holds ( Z in Q iff ( Z in bool the carrier of V & S1[Z] ) ) from XBOOLE_0:sch_1(); A4: now__::_thesis:_for_Z_being_set_st_Z_<>_{}_&_Z_c=_Q_&_Z_is_c=-linear_holds_ union_Z_in_Q let Z be set ; ::_thesis: ( Z <> {} & Z c= Q & Z is c=-linear implies union Z in Q ) assume that A5: Z <> {} and A6: Z c= Q and A7: Z is c=-linear ; ::_thesis: union Z in Q set W = union Z; union Z c= the carrier of V proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in union Z or x in the carrier of V ) assume x in union Z ; ::_thesis: x in the carrier of V then consider X being set such that A8: x in X and A9: X in Z by TARSKI:def_4; X in bool the carrier of V by A3, A6, A9; hence x in the carrier of V by A8; ::_thesis: verum end; then reconsider W = union Z as Subset of V ; set y = the Element of Z; the Element of Z in Q by A5, A6, TARSKI:def_3; then A10: ex I being Subset of V st ( I = the Element of Z & A c= I & I c= B & I is linearly-independent ) by A3; A11: W is linearly-independent proof deffunc H1( set ) -> set = { D where D is Subset of V : ( $1 in D & D in Z ) } ; let l be Linear_Combination of W; :: according to RLVECT_3:def_1 ::_thesis: ( not Sum l = 0. V or Carrier l = {} ) assume that A12: Sum l = 0. V and A13: Carrier l <> {} ; ::_thesis: contradiction consider f being Function such that A14: dom f = Carrier l and A15: for x being set st x in Carrier l holds f . x = H1(x) from FUNCT_1:sch_3(); reconsider M = rng f as non empty set by A13, A14, RELAT_1:42; A16: now__::_thesis:_not_{}_in_M assume {} in M ; ::_thesis: contradiction then consider x being set such that A17: x in dom f and A18: f . x = {} by FUNCT_1:def_3; Carrier l c= W by RLVECT_2:def_6; then consider X being set such that A19: x in X and A20: X in Z by A14, A17, TARSKI:def_4; reconsider X = X as Subset of V by A3, A6, A20; X in { D where D is Subset of V : ( x in D & D in Z ) } by A19, A20; hence contradiction by A14, A15, A17, A18; ::_thesis: verum end; set F = the Choice_Function of M; set S = rng the Choice_Function of M; the Element of M in M ; then A21: union M <> {} by A16, ORDERS_1:6; then A22: dom the Choice_Function of M = M by FUNCT_2:def_1; A23: now__::_thesis:_for_X_being_set_st_X_in_rng_the_Choice_Function_of_M_holds_ X_in_Z let X be set ; ::_thesis: ( X in rng the Choice_Function of M implies X in Z ) assume X in rng the Choice_Function of M ; ::_thesis: X in Z then consider x being set such that A24: x in dom the Choice_Function of M and A25: the Choice_Function of M . x = X by FUNCT_1:def_3; consider y being set such that A26: ( y in dom f & f . y = x ) by A22, A24, FUNCT_1:def_3; A27: x = { D where D is Subset of V : ( y in D & D in Z ) } by A14, A15, A26; X in x by A16, A22, A24, A25, ORDERS_1:def_1; then ex D being Subset of V st ( D = X & y in D & D in Z ) by A27; hence X in Z ; ::_thesis: verum end; A28: now__::_thesis:_for_X,_Y_being_set_st_X_in_rng_the_Choice_Function_of_M_&_Y_in_rng_the_Choice_Function_of_M_&_not_X_c=_Y_holds_ Y_c=_X let X, Y be set ; ::_thesis: ( X in rng the Choice_Function of M & Y in rng the Choice_Function of M & not X c= Y implies Y c= X ) assume ( X in rng the Choice_Function of M & Y in rng the Choice_Function of M ) ; ::_thesis: ( X c= Y or Y c= X ) then ( X in Z & Y in Z ) by A23; then X,Y are_c=-comparable by A7, ORDINAL1:def_8; hence ( X c= Y or Y c= X ) by XBOOLE_0:def_9; ::_thesis: verum end; dom the Choice_Function of M is finite by A14, A22, FINSET_1:8; then rng the Choice_Function of M is finite by FINSET_1:8; then union (rng the Choice_Function of M) in rng the Choice_Function of M by A21, A28, CARD_2:62; then union (rng the Choice_Function of M) in Z by A23; then consider I being Subset of V such that A29: I = union (rng the Choice_Function of M) and A c= I and I c= B and A30: I is linearly-independent by A3, A6; Carrier l c= union (rng the Choice_Function of M) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Carrier l or x in union (rng the Choice_Function of M) ) assume A31: x in Carrier l ; ::_thesis: x in union (rng the Choice_Function of M) then A32: f . x = { D where D is Subset of V : ( x in D & D in Z ) } by A15; A33: f . x in M by A14, A31, FUNCT_1:def_3; then the Choice_Function of M . (f . x) in f . x by A16, ORDERS_1:def_1; then A34: ex D being Subset of V st ( the Choice_Function of M . (f . x) = D & x in D & D in Z ) by A32; the Choice_Function of M . (f . x) in rng the Choice_Function of M by A22, A33, FUNCT_1:def_3; hence x in union (rng the Choice_Function of M) by A34, TARSKI:def_4; ::_thesis: verum end; then l is Linear_Combination of I by A29, RLVECT_2:def_6; hence contradiction by A12, A13, A30, RLVECT_3:def_1; ::_thesis: verum end; A35: W c= B proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in W or x in B ) assume x in W ; ::_thesis: x in B then consider X being set such that A36: x in X and A37: X in Z by TARSKI:def_4; ex I being Subset of V st ( I = X & A c= I & I c= B & I is linearly-independent ) by A3, A6, A37; hence x in B by A36; ::_thesis: verum end; the Element of Z c= W by A5, ZFMISC_1:74; then A c= W by A10, XBOOLE_1:1; hence union Z in Q by A3, A11, A35; ::_thesis: verum end; Q <> {} by A1, A3; then consider X being set such that A38: X in Q and A39: for Z being set st Z in Q & Z <> X holds not X c= Z by A4, ORDERS_1:67; consider I being Subset of V such that A40: I = X and A41: A c= I and A42: I c= B and A43: I is linearly-independent by A3, A38; reconsider I = I as linearly-independent Subset of V by A43; take I ; ::_thesis: ( A c= I & I c= B & Lin I = V ) thus ( A c= I & I c= B ) by A41, A42; ::_thesis: Lin I = V assume A44: Lin I <> V ; ::_thesis: contradiction now__::_thesis:_ex_v_being_VECTOR_of_V_st_ (_v_in_B_&_not_v_in_Lin_I_) assume A45: for v being VECTOR of V st v in B holds v in Lin I ; ::_thesis: contradiction now__::_thesis:_for_v_being_VECTOR_of_V_st_v_in_Lin_B_holds_ v_in_Lin_I let v be VECTOR of V; ::_thesis: ( v in Lin B implies v in Lin I ) assume v in Lin B ; ::_thesis: v in Lin I then consider l being Linear_Combination of B such that A46: v = Sum l by RLVECT_3:14; Carrier l c= the carrier of (Lin I) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Carrier l or x in the carrier of (Lin I) ) assume A47: x in Carrier l ; ::_thesis: x in the carrier of (Lin I) then reconsider a = x as VECTOR of V ; Carrier l c= B by RLVECT_2:def_6; then a in Lin I by A45, A47; hence x in the carrier of (Lin I) by STRUCT_0:def_5; ::_thesis: verum end; then reconsider l = l as Linear_Combination of Up (Lin I) by RLVECT_2:def_6; Sum l = v by A46; then v in Lin (Up (Lin I)) by RLVECT_3:14; hence v in Lin I by RLVECT_3:18; ::_thesis: verum end; then Lin B is Subspace of Lin I by RLSUB_1:29; hence contradiction by A2, A44, RLSUB_1:26; ::_thesis: verum end; then consider v being VECTOR of V such that A48: v in B and A49: not v in Lin I ; A50: not v in I by A49, RLVECT_3:15; {v} c= B by A48, ZFMISC_1:31; then A51: I \/ {v} c= B by A42, XBOOLE_1:8; v in {v} by TARSKI:def_1; then A52: v in I \/ {v} by XBOOLE_0:def_3; A53: I \/ {v} is linearly-independent proof let l be Linear_Combination of I \/ {v}; :: according to RLVECT_3:def_1 ::_thesis: ( not Sum l = 0. V or Carrier l = {} ) assume A54: Sum l = 0. V ; ::_thesis: Carrier l = {} percases ( v in Carrier l or not v in Carrier l ) ; suppose v in Carrier l ; ::_thesis: Carrier l = {} then A55: - (l . v) <> 0 by RLVECT_2:19; deffunc H1( VECTOR of V) -> Element of NAT = 0 ; deffunc H2( VECTOR of V) -> Element of REAL = l . $1; consider f being Function of the carrier of V,REAL such that A56: f . v = 0 and A57: for u being Element of V st u <> v holds f . u = H2(u) from FUNCT_2:sch_6(); reconsider f = f as Element of Funcs ( the carrier of V,REAL) by FUNCT_2:8; now__::_thesis:_for_u_being_Element_of_V_st_not_u_in_(Carrier_l)_\_{v}_holds_ f_._u_=_0 let u be Element of V; ::_thesis: ( not u in (Carrier l) \ {v} implies f . u = 0 ) assume not u in (Carrier l) \ {v} ; ::_thesis: f . u = 0 then ( not u in Carrier l or u in {v} ) by XBOOLE_0:def_5; then ( ( l . u = 0 & u <> v ) or u = v ) by TARSKI:def_1; hence f . u = 0 by A56, A57; ::_thesis: verum end; then reconsider f = f as Linear_Combination of V by RLVECT_2:def_3; Carrier f c= I proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Carrier f or x in I ) assume x in Carrier f ; ::_thesis: x in I then consider u being Element of V such that A58: u = x and A59: f . u <> 0 ; f . u = l . u by A56, A57, A59; then ( Carrier l c= I \/ {v} & u in Carrier l ) by A59, RLVECT_2:def_6; then ( u in I or u in {v} ) by XBOOLE_0:def_3; hence x in I by A56, A58, A59, TARSKI:def_1; ::_thesis: verum end; then reconsider f = f as Linear_Combination of I by RLVECT_2:def_6; consider g being Function of the carrier of V,REAL such that A60: g . v = - (l . v) and A61: for u being Element of V st u <> v holds g . u = H1(u) from FUNCT_2:sch_6(); reconsider g = g as Element of Funcs ( the carrier of V,REAL) by FUNCT_2:8; now__::_thesis:_for_u_being_Element_of_V_st_not_u_in_{v}_holds_ g_._u_=_0 let u be Element of V; ::_thesis: ( not u in {v} implies g . u = 0 ) assume not u in {v} ; ::_thesis: g . u = 0 then u <> v by TARSKI:def_1; hence g . u = 0 by A61; ::_thesis: verum end; then reconsider g = g as Linear_Combination of V by RLVECT_2:def_3; Carrier g c= {v} proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Carrier g or x in {v} ) assume x in Carrier g ; ::_thesis: x in {v} then ex u being Element of V st ( x = u & g . u <> 0 ) ; then x = v by A61; hence x in {v} by TARSKI:def_1; ::_thesis: verum end; then reconsider g = g as Linear_Combination of {v} by RLVECT_2:def_6; A62: Sum g = (- (l . v)) * v by A60, RLVECT_2:32; now__::_thesis:_for_u_being_Element_of_V_holds_(f_-_g)_._u_=_l_._u let u be Element of V; ::_thesis: (f - g) . u = l . u now__::_thesis:_(f_-_g)_._u_=_l_._u percases ( v = u or v <> u ) ; supposeA63: v = u ; ::_thesis: (f - g) . u = l . u thus (f - g) . u = (f . u) - (g . u) by RLVECT_2:54 .= l . u by A56, A60, A63 ; ::_thesis: verum end; supposeA64: v <> u ; ::_thesis: (f - g) . u = l . u thus (f - g) . u = (f . u) - (g . u) by RLVECT_2:54 .= (l . u) - (g . u) by A57, A64 .= (l . u) - 0 by A61, A64 .= l . u ; ::_thesis: verum end; end; end; hence (f - g) . u = l . u ; ::_thesis: verum end; then f - g = l by RLVECT_2:def_9; then 0. V = (Sum f) - (Sum g) by A54, RLVECT_3:4; then Sum f = (0. V) + (Sum g) by RLSUB_2:61 .= (- (l . v)) * v by A62, RLVECT_1:4 ; then A65: (- (l . v)) * v in Lin I by RLVECT_3:14; ((- (l . v)) ") * ((- (l . v)) * v) = (((- (l . v)) ") * (- (l . v))) * v by RLVECT_1:def_7 .= 1 * v by A55, XCMPLX_0:def_7 .= v by RLVECT_1:def_8 ; hence Carrier l = {} by A49, A65, RLSUB_1:21; ::_thesis: verum end; supposeA66: not v in Carrier l ; ::_thesis: Carrier l = {} Carrier l c= I proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Carrier l or x in I ) assume A67: x in Carrier l ; ::_thesis: x in I Carrier l c= I \/ {v} by RLVECT_2:def_6; then ( x in I or x in {v} ) by A67, XBOOLE_0:def_3; hence x in I by A66, A67, TARSKI:def_1; ::_thesis: verum end; then l is Linear_Combination of I by RLVECT_2:def_6; hence Carrier l = {} by A54, RLVECT_3:def_1; ::_thesis: verum end; end; end; A c= I \/ {v} by A41, XBOOLE_1:10; then I \/ {v} in Q by A3, A51, A53; hence contradiction by A39, A40, A50, A52, XBOOLE_1:7; ::_thesis: verum end; begin definition let G be non empty right_complementable Abelian add-associative right_zeroed addLoopStr ; let LG be Linear_Combination of G; let g be Element of G; funcg + LG -> Linear_Combination of G means :Def1: :: RLAFFIN1:def 1 for h being Element of G holds it . h = LG . (h - g); existence ex b1 being Linear_Combination of G st for h being Element of G holds b1 . h = LG . (h - g) proof deffunc H1( Element of G) -> Element of the carrier of G = g + $1; set vC = { H1(h) where h is Element of G : h in Carrier LG } ; A1: { H1(h) where h is Element of G : h in Carrier LG } c= the carrier of G proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in { H1(h) where h is Element of G : h in Carrier LG } or x in the carrier of G ) assume x in { H1(h) where h is Element of G : h in Carrier LG } ; ::_thesis: x in the carrier of G then ex h being Element of G st ( x = H1(h) & h in Carrier LG ) ; hence x in the carrier of G ; ::_thesis: verum end; A2: Carrier LG is finite ; { H1(h) where h is Element of G : h in Carrier LG } is finite from FRAENKEL:sch_21(A2); then reconsider vC = { H1(h) where h is Element of G : h in Carrier LG } as finite Subset of G by A1; deffunc H2( Element of G) -> Element of REAL = LG . ($1 - g); consider f being Function of the carrier of G,REAL such that A3: for h being Element of G holds f . h = H2(h) from FUNCT_2:sch_4(); reconsider f = f as Element of Funcs ( the carrier of G,REAL) by FUNCT_2:8; now__::_thesis:_for_h_being_Element_of_G_st_not_h_in_vC_holds_ not_f_._h_<>_0 let h be Element of G; ::_thesis: ( not h in vC implies not f . h <> 0 ) assume A4: not h in vC ; ::_thesis: not f . h <> 0 assume f . h <> 0 ; ::_thesis: contradiction then LG . (h - g) <> 0 by A3; then A5: h - g in Carrier LG ; g + (h - g) = (h + (- g)) + g by RLVECT_1:def_11 .= h + (g + (- g)) by RLVECT_1:def_3 .= h + (0. G) by RLVECT_1:def_10 .= h by RLVECT_1:4 ; hence contradiction by A4, A5; ::_thesis: verum end; then reconsider f = f as Linear_Combination of G by RLVECT_2:def_3; take f ; ::_thesis: for h being Element of G holds f . h = LG . (h - g) thus for h being Element of G holds f . h = LG . (h - g) by A3; ::_thesis: verum end; uniqueness for b1, b2 being Linear_Combination of G st ( for h being Element of G holds b1 . h = LG . (h - g) ) & ( for h being Element of G holds b2 . h = LG . (h - g) ) holds b1 = b2 proof let L1, L2 be Linear_Combination of G; ::_thesis: ( ( for h being Element of G holds L1 . h = LG . (h - g) ) & ( for h being Element of G holds L2 . h = LG . (h - g) ) implies L1 = L2 ) assume that A6: for h being Element of G holds L1 . h = LG . (h - g) and A7: for h being Element of G holds L2 . h = LG . (h - g) ; ::_thesis: L1 = L2 now__::_thesis:_for_h_being_Element_of_G_holds_L1_._h_=_L2_._h let h be Element of G; ::_thesis: L1 . h = L2 . h thus L1 . h = LG . (h - g) by A6 .= L2 . h by A7 ; ::_thesis: verum end; hence L1 = L2 by RLVECT_2:def_9; ::_thesis: verum end; end; :: deftheorem Def1 defines + RLAFFIN1:def_1_:_ for G being non empty right_complementable Abelian add-associative right_zeroed addLoopStr for LG being Linear_Combination of G for g being Element of G for b4 being Linear_Combination of G holds ( b4 = g + LG iff for h being Element of G holds b4 . h = LG . (h - g) ); theorem Th16: :: RLAFFIN1:16 for G being non empty right_complementable Abelian add-associative right_zeroed addLoopStr for LG being Linear_Combination of G for g being Element of G holds Carrier (g + LG) = g + (Carrier LG) proof let G be non empty right_complementable Abelian add-associative right_zeroed addLoopStr ; ::_thesis: for LG being Linear_Combination of G for g being Element of G holds Carrier (g + LG) = g + (Carrier LG) let LG be Linear_Combination of G; ::_thesis: for g being Element of G holds Carrier (g + LG) = g + (Carrier LG) let g be Element of G; ::_thesis: Carrier (g + LG) = g + (Carrier LG) thus Carrier (g + LG) c= g + (Carrier LG) :: according to XBOOLE_0:def_10 ::_thesis: g + (Carrier LG) c= Carrier (g + LG) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Carrier (g + LG) or x in g + (Carrier LG) ) assume A1: x in Carrier (g + LG) ; ::_thesis: x in g + (Carrier LG) reconsider w = x as Element of G by A1; A2: (g + LG) . w <> 0 by A1, RLVECT_2:19; A3: g + (w - g) = (w + (- g)) + g by RLVECT_1:def_11 .= w + (g + (- g)) by RLVECT_1:def_3 .= w + (0. G) by RLVECT_1:def_10 .= w by RLVECT_1:4 ; (g + LG) . w = LG . (w - g) by Def1; then w - g in Carrier LG by A2; hence x in g + (Carrier LG) by A3; ::_thesis: verum end; let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in g + (Carrier LG) or x in Carrier (g + LG) ) assume x in g + (Carrier LG) ; ::_thesis: x in Carrier (g + LG) then consider w being Element of G such that A4: x = g + w and A5: w in Carrier LG ; (g + w) - g = (g + w) + (- g) by RLVECT_1:def_11 .= ((- g) + g) + w by RLVECT_1:def_3 .= (0. G) + w by RLVECT_1:5 .= w by RLVECT_1:4 ; then A6: (g + LG) . (g + w) = LG . w by Def1; LG . w <> 0 by A5, RLVECT_2:19; hence x in Carrier (g + LG) by A4, A6; ::_thesis: verum end; theorem Th17: :: RLAFFIN1:17 for G being non empty right_complementable Abelian add-associative right_zeroed addLoopStr for LG1, LG2 being Linear_Combination of G for g being Element of G holds g + (LG1 + LG2) = (g + LG1) + (g + LG2) proof let G be non empty right_complementable Abelian add-associative right_zeroed addLoopStr ; ::_thesis: for LG1, LG2 being Linear_Combination of G for g being Element of G holds g + (LG1 + LG2) = (g + LG1) + (g + LG2) let LG1, LG2 be Linear_Combination of G; ::_thesis: for g being Element of G holds g + (LG1 + LG2) = (g + LG1) + (g + LG2) let g be Element of G; ::_thesis: g + (LG1 + LG2) = (g + LG1) + (g + LG2) now__::_thesis:_for_h_being_Element_of_G_holds_(g_+_(LG1_+_LG2))_._h_=_((g_+_LG1)_+_(g_+_LG2))_._h let h be Element of G; ::_thesis: (g + (LG1 + LG2)) . h = ((g + LG1) + (g + LG2)) . h thus (g + (LG1 + LG2)) . h = (LG1 + LG2) . (h - g) by Def1 .= (LG1 . (h - g)) + (LG2 . (h - g)) by RLVECT_2:def_10 .= ((g + LG1) . h) + (LG2 . (h - g)) by Def1 .= ((g + LG1) . h) + ((g + LG2) . h) by Def1 .= ((g + LG1) + (g + LG2)) . h by RLVECT_2:def_10 ; ::_thesis: verum end; hence g + (LG1 + LG2) = (g + LG1) + (g + LG2) by RLVECT_2:def_9; ::_thesis: verum end; theorem :: RLAFFIN1:18 for r being Real for V being RealLinearSpace for v being VECTOR of V for L being Linear_Combination of V holds v + (r * L) = r * (v + L) proof let r be Real; ::_thesis: for V being RealLinearSpace for v being VECTOR of V for L being Linear_Combination of V holds v + (r * L) = r * (v + L) let V be RealLinearSpace; ::_thesis: for v being VECTOR of V for L being Linear_Combination of V holds v + (r * L) = r * (v + L) let v be VECTOR of V; ::_thesis: for L being Linear_Combination of V holds v + (r * L) = r * (v + L) let L be Linear_Combination of V; ::_thesis: v + (r * L) = r * (v + L) now__::_thesis:_for_w_being_VECTOR_of_V_holds_(v_+_(r_*_L))_._w_=_(r_*_(v_+_L))_._w let w be VECTOR of V; ::_thesis: (v + (r * L)) . w = (r * (v + L)) . w thus (v + (r * L)) . w = (r * L) . (w - v) by Def1 .= r * (L . (w - v)) by RLVECT_2:def_11 .= r * ((v + L) . w) by Def1 .= (r * (v + L)) . w by RLVECT_2:def_11 ; ::_thesis: verum end; hence v + (r * L) = r * (v + L) by RLVECT_2:def_9; ::_thesis: verum end; theorem Th19: :: RLAFFIN1:19 for G being non empty right_complementable Abelian add-associative right_zeroed addLoopStr for LG being Linear_Combination of G for g, h being Element of G holds g + (h + LG) = (g + h) + LG proof let G be non empty right_complementable Abelian add-associative right_zeroed addLoopStr ; ::_thesis: for LG being Linear_Combination of G for g, h being Element of G holds g + (h + LG) = (g + h) + LG let LG be Linear_Combination of G; ::_thesis: for g, h being Element of G holds g + (h + LG) = (g + h) + LG let g, h be Element of G; ::_thesis: g + (h + LG) = (g + h) + LG now__::_thesis:_for_s_being_Element_of_G_holds_(g_+_(h_+_LG))_._s_=_((g_+_h)_+_LG)_._s let s be Element of G; ::_thesis: (g + (h + LG)) . s = ((g + h) + LG) . s thus (g + (h + LG)) . s = (h + LG) . (s - g) by Def1 .= LG . ((s - g) - h) by Def1 .= LG . (s - (g + h)) by RLVECT_1:27 .= ((g + h) + LG) . s by Def1 ; ::_thesis: verum end; hence g + (h + LG) = (g + h) + LG by RLVECT_2:def_9; ::_thesis: verum end; theorem Th20: :: RLAFFIN1:20 for G being non empty right_complementable Abelian add-associative right_zeroed addLoopStr for g being Element of G holds g + (ZeroLC G) = ZeroLC G proof let G be non empty right_complementable Abelian add-associative right_zeroed addLoopStr ; ::_thesis: for g being Element of G holds g + (ZeroLC G) = ZeroLC G let g be Element of G; ::_thesis: g + (ZeroLC G) = ZeroLC G Carrier (ZeroLC G) = {} G by RLVECT_2:def_5; then {} G = g + (Carrier (ZeroLC G)) by Th8 .= Carrier (g + (ZeroLC G)) by Th16 ; hence g + (ZeroLC G) = ZeroLC G by RLVECT_2:def_5; ::_thesis: verum end; theorem Th21: :: RLAFFIN1:21 for G being non empty right_complementable Abelian add-associative right_zeroed addLoopStr for LG being Linear_Combination of G holds (0. G) + LG = LG proof let G be non empty right_complementable Abelian add-associative right_zeroed addLoopStr ; ::_thesis: for LG being Linear_Combination of G holds (0. G) + LG = LG let LG be Linear_Combination of G; ::_thesis: (0. G) + LG = LG now__::_thesis:_for_g_being_Element_of_G_holds_((0._G)_+_LG)_._g_=_LG_._g let g be Element of G; ::_thesis: ((0. G) + LG) . g = LG . g thus ((0. G) + LG) . g = LG . (g - (0. G)) by Def1 .= LG . g by RLVECT_1:13 ; ::_thesis: verum end; hence (0. G) + LG = LG by RLVECT_2:def_9; ::_thesis: verum end; definition let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; let LR be Linear_Combination of R; let r be Real; funcr (*) LR -> Linear_Combination of R means :Def2: :: RLAFFIN1:def 2 for v being Element of R holds it . v = LR . ((r ") * v) if r <> 0 otherwise it = ZeroLC R; existence ( ( r <> 0 implies ex b1 being Linear_Combination of R st for v being Element of R holds b1 . v = LR . ((r ") * v) ) & ( not r <> 0 implies ex b1 being Linear_Combination of R st b1 = ZeroLC R ) ) proof now__::_thesis:_(_r_<>_0_implies_ex_f_being_Linear_Combination_of_R_st_ for_v_being_Element_of_R_holds_ (_(_r_<>_0_implies_ex_b3_being_Linear_Combination_of_R_st_ for_v_being_Element_of_R_holds_b3_._v_=_LR_._((r_")_*_v)_)_&_(_not_r_<>_0_implies_ex_b3_being_Linear_Combination_of_R_st_b3_=_ZeroLC_R_)_)_) deffunc H1( Element of R) -> Element of REAL = LR . ((r ") * $1); deffunc H2( Element of R) -> Element of the carrier of R = r * $1; consider f being Function of the carrier of R,REAL such that A1: for v being Element of R holds f . v = H1(v) from FUNCT_2:sch_4(); reconsider f = f as Element of Funcs ( the carrier of R,REAL) by FUNCT_2:8; assume A2: r <> 0 ; ::_thesis: ex f being Linear_Combination of R st for v being Element of R holds ( ( r <> 0 implies ex b3 being Linear_Combination of R st for v being Element of R holds b3 . v = LR . ((r ") * v) ) & ( not r <> 0 implies ex b3 being Linear_Combination of R st b3 = ZeroLC R ) ) A3: now__::_thesis:_for_v_being_Element_of_R_st_not_v_in_r_*_(Carrier_LR)_holds_ not_f_._v_<>_0 let v be Element of R; ::_thesis: ( not v in r * (Carrier LR) implies not f . v <> 0 ) assume A4: not v in r * (Carrier LR) ; ::_thesis: not f . v <> 0 A5: f . v = LR . ((r ") * v) by A1; A6: r * ((r ") * v) = (r * (r ")) * v by RLVECT_1:def_7 .= 1 * v by A2, XCMPLX_0:def_7 .= v by RLVECT_1:def_8 ; assume f . v <> 0 ; ::_thesis: contradiction then (r ") * v in Carrier LR by A5; hence contradiction by A4, A6; ::_thesis: verum end; A7: Carrier LR is finite ; { H2(w) where w is Element of R : w in Carrier LR } is finite from FRAENKEL:sch_21(A7); then reconsider f = f as Linear_Combination of R by A3, RLVECT_2:def_3; take f = f; ::_thesis: for v being Element of R holds ( ( r <> 0 implies ex b2 being Linear_Combination of R st for v being Element of R holds b2 . v = LR . ((r ") * v) ) & ( not r <> 0 implies ex b2 being Linear_Combination of R st b2 = ZeroLC R ) ) let v be Element of R; ::_thesis: ( ( r <> 0 implies ex b1 being Linear_Combination of R st for v being Element of R holds b1 . v = LR . ((r ") * v) ) & ( not r <> 0 implies ex b1 being Linear_Combination of R st b1 = ZeroLC R ) ) f . v = LR . ((r ") * v) by A1; hence ( ( r <> 0 implies ex b1 being Linear_Combination of R st for v being Element of R holds b1 . v = LR . ((r ") * v) ) & ( not r <> 0 implies ex b1 being Linear_Combination of R st b1 = ZeroLC R ) ) by A1; ::_thesis: verum end; hence ( ( r <> 0 implies ex b1 being Linear_Combination of R st for v being Element of R holds b1 . v = LR . ((r ") * v) ) & ( not r <> 0 implies ex b1 being Linear_Combination of R st b1 = ZeroLC R ) ) ; ::_thesis: verum end; uniqueness for b1, b2 being Linear_Combination of R holds ( ( r <> 0 & ( for v being Element of R holds b1 . v = LR . ((r ") * v) ) & ( for v being Element of R holds b2 . v = LR . ((r ") * v) ) implies b1 = b2 ) & ( not r <> 0 & b1 = ZeroLC R & b2 = ZeroLC R implies b1 = b2 ) ) proof now__::_thesis:_for_L1,_L2_being_Linear_Combination_of_R_st_(_for_v_being_Element_of_R_holds_L1_._v_=_LR_._((r_")_*_v)_)_&_(_for_v_being_Element_of_R_holds_L2_._v_=_LR_._((r_")_*_v)_)_holds_ L1_=_L2 let L1, L2 be Linear_Combination of R; ::_thesis: ( ( for v being Element of R holds L1 . v = LR . ((r ") * v) ) & ( for v being Element of R holds L2 . v = LR . ((r ") * v) ) implies L1 = L2 ) assume that A8: for v being Element of R holds L1 . v = LR . ((r ") * v) and A9: for v being Element of R holds L2 . v = LR . ((r ") * v) ; ::_thesis: L1 = L2 now__::_thesis:_for_v_being_Element_of_R_holds_L1_._v_=_L2_._v let v be Element of R; ::_thesis: L1 . v = L2 . v thus L1 . v = LR . ((r ") * v) by A8 .= L2 . v by A9 ; ::_thesis: verum end; hence L1 = L2 by RLVECT_2:def_9; ::_thesis: verum end; hence for b1, b2 being Linear_Combination of R holds ( ( r <> 0 & ( for v being Element of R holds b1 . v = LR . ((r ") * v) ) & ( for v being Element of R holds b2 . v = LR . ((r ") * v) ) implies b1 = b2 ) & ( not r <> 0 & b1 = ZeroLC R & b2 = ZeroLC R implies b1 = b2 ) ) ; ::_thesis: verum end; consistency for b1 being Linear_Combination of R holds verum ; end; :: deftheorem Def2 defines (*) RLAFFIN1:def_2_:_ for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR being Linear_Combination of R for r being Real for b4 being Linear_Combination of R holds ( ( r <> 0 implies ( b4 = r (*) LR iff for v being Element of R holds b4 . v = LR . ((r ") * v) ) ) & ( not r <> 0 implies ( b4 = r (*) LR iff b4 = ZeroLC R ) ) ); theorem Th22: :: RLAFFIN1:22 for r being Real for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR being Linear_Combination of R holds Carrier (r (*) LR) c= r * (Carrier LR) proof let r be Real; ::_thesis: for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR being Linear_Combination of R holds Carrier (r (*) LR) c= r * (Carrier LR) let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: for LR being Linear_Combination of R holds Carrier (r (*) LR) c= r * (Carrier LR) let LR be Linear_Combination of R; ::_thesis: Carrier (r (*) LR) c= r * (Carrier LR) let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Carrier (r (*) LR) or x in r * (Carrier LR) ) assume A1: x in Carrier (r (*) LR) ; ::_thesis: x in r * (Carrier LR) reconsider v = x as Element of R by A1; A2: (r (*) LR) . v <> 0 by A1, RLVECT_2:19; 0 (*) LR = ZeroLC R by Def2; then A3: r <> 0 by A1, RLVECT_2:def_5; then (r (*) LR) . v = LR . ((r ") * v) by Def2; then A4: (r ") * v in Carrier LR by A2; r * ((r ") * v) = (r * (r ")) * v by RLVECT_1:def_7 .= 1 * v by A3, XCMPLX_0:def_7 .= v by RLVECT_1:def_8 ; hence x in r * (Carrier LR) by A4; ::_thesis: verum end; theorem Th23: :: RLAFFIN1:23 for r being Real for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR being Linear_Combination of R st r <> 0 holds Carrier (r (*) LR) = r * (Carrier LR) proof let r be Real; ::_thesis: for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR being Linear_Combination of R st r <> 0 holds Carrier (r (*) LR) = r * (Carrier LR) let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: for LR being Linear_Combination of R st r <> 0 holds Carrier (r (*) LR) = r * (Carrier LR) let LR be Linear_Combination of R; ::_thesis: ( r <> 0 implies Carrier (r (*) LR) = r * (Carrier LR) ) assume A1: r <> 0 ; ::_thesis: Carrier (r (*) LR) = r * (Carrier LR) thus Carrier (r (*) LR) c= r * (Carrier LR) by Th22; :: according to XBOOLE_0:def_10 ::_thesis: r * (Carrier LR) c= Carrier (r (*) LR) let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in r * (Carrier LR) or x in Carrier (r (*) LR) ) assume x in r * (Carrier LR) ; ::_thesis: x in Carrier (r (*) LR) then consider v being Element of R such that A2: x = r * v and A3: v in Carrier LR ; (r ") * (r * v) = ((r ") * r) * v by RLVECT_1:def_7 .= 1 * v by A1, XCMPLX_0:def_7 .= v by RLVECT_1:def_8 ; then A4: LR . v = (r (*) LR) . x by A1, A2, Def2; LR . v <> 0 by A3, RLVECT_2:19; hence x in Carrier (r (*) LR) by A2, A4; ::_thesis: verum end; theorem Th24: :: RLAFFIN1:24 for r being Real for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR1, LR2 being Linear_Combination of R holds r (*) (LR1 + LR2) = (r (*) LR1) + (r (*) LR2) proof let r be Real; ::_thesis: for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR1, LR2 being Linear_Combination of R holds r (*) (LR1 + LR2) = (r (*) LR1) + (r (*) LR2) let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: for LR1, LR2 being Linear_Combination of R holds r (*) (LR1 + LR2) = (r (*) LR1) + (r (*) LR2) let LR1, LR2 be Linear_Combination of R; ::_thesis: r (*) (LR1 + LR2) = (r (*) LR1) + (r (*) LR2) percases ( r = 0 or r <> 0 ) ; supposeA1: r = 0 ; ::_thesis: r (*) (LR1 + LR2) = (r (*) LR1) + (r (*) LR2) set Z = ZeroLC R; A2: now__::_thesis:_for_v_being_Element_of_R_holds_((ZeroLC_R)_+_(ZeroLC_R))_._v_=_(ZeroLC_R)_._v let v be Element of R; ::_thesis: ((ZeroLC R) + (ZeroLC R)) . v = (ZeroLC R) . v thus ((ZeroLC R) + (ZeroLC R)) . v = ((ZeroLC R) . v) + ((ZeroLC R) . v) by RLVECT_2:def_10 .= ((ZeroLC R) . v) + 0 by RLVECT_2:20 .= (ZeroLC R) . v ; ::_thesis: verum end; thus r (*) (LR1 + LR2) = ZeroLC R by A1, Def2 .= (ZeroLC R) + (ZeroLC R) by A2, RLVECT_2:def_9 .= (r (*) LR1) + (ZeroLC R) by A1, Def2 .= (r (*) LR1) + (r (*) LR2) by A1, Def2 ; ::_thesis: verum end; supposeA3: r <> 0 ; ::_thesis: r (*) (LR1 + LR2) = (r (*) LR1) + (r (*) LR2) now__::_thesis:_for_v_being_Element_of_R_holds_(r_(*)_(LR1_+_LR2))_._v_=_((r_(*)_LR1)_+_(r_(*)_LR2))_._v let v be Element of R; ::_thesis: (r (*) (LR1 + LR2)) . v = ((r (*) LR1) + (r (*) LR2)) . v thus (r (*) (LR1 + LR2)) . v = (LR1 + LR2) . ((r ") * v) by A3, Def2 .= (LR1 . ((r ") * v)) + (LR2 . ((r ") * v)) by RLVECT_2:def_10 .= ((r (*) LR1) . v) + (LR2 . ((r ") * v)) by A3, Def2 .= ((r (*) LR1) . v) + ((r (*) LR2) . v) by A3, Def2 .= ((r (*) LR1) + (r (*) LR2)) . v by RLVECT_2:def_10 ; ::_thesis: verum end; hence r (*) (LR1 + LR2) = (r (*) LR1) + (r (*) LR2) by RLVECT_2:def_9; ::_thesis: verum end; end; end; theorem :: RLAFFIN1:25 for r, s being Real for V being RealLinearSpace for L being Linear_Combination of V holds r * (s (*) L) = s (*) (r * L) proof let r, s be Real; ::_thesis: for V being RealLinearSpace for L being Linear_Combination of V holds r * (s (*) L) = s (*) (r * L) let V be RealLinearSpace; ::_thesis: for L being Linear_Combination of V holds r * (s (*) L) = s (*) (r * L) let L be Linear_Combination of V; ::_thesis: r * (s (*) L) = s (*) (r * L) percases ( s = 0 or s <> 0 ) ; supposeA1: s = 0 ; ::_thesis: r * (s (*) L) = s (*) (r * L) hence r * (s (*) L) = r * (ZeroLC V) by Def2 .= r * (0 * L) by RLVECT_2:43 .= (r * 0) * L by RLVECT_2:47 .= ZeroLC V by RLVECT_2:43 .= s (*) (r * L) by A1, Def2 ; ::_thesis: verum end; supposeA2: s <> 0 ; ::_thesis: r * (s (*) L) = s (*) (r * L) now__::_thesis:_for_v_being_VECTOR_of_V_holds_(r_*_(s_(*)_L))_._v_=_(s_(*)_(r_*_L))_._v let v be VECTOR of V; ::_thesis: (r * (s (*) L)) . v = (s (*) (r * L)) . v thus (r * (s (*) L)) . v = r * ((s (*) L) . v) by RLVECT_2:def_11 .= r * (L . ((s ") * v)) by A2, Def2 .= (r * L) . ((s ") * v) by RLVECT_2:def_11 .= (s (*) (r * L)) . v by A2, Def2 ; ::_thesis: verum end; hence r * (s (*) L) = s (*) (r * L) by RLVECT_2:def_9; ::_thesis: verum end; end; end; theorem Th26: :: RLAFFIN1:26 for r being Real for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct holds r (*) (ZeroLC R) = ZeroLC R proof let r be Real; ::_thesis: for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct holds r (*) (ZeroLC R) = ZeroLC R let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: r (*) (ZeroLC R) = ZeroLC R percases ( r = 0 or r <> 0 ) ; suppose r = 0 ; ::_thesis: r (*) (ZeroLC R) = ZeroLC R hence r (*) (ZeroLC R) = ZeroLC R by Def2; ::_thesis: verum end; supposeA1: r <> 0 ; ::_thesis: r (*) (ZeroLC R) = ZeroLC R now__::_thesis:_for_v_being_Element_of_R_holds_(r_(*)_(ZeroLC_R))_._v_=_(ZeroLC_R)_._v let v be Element of R; ::_thesis: (r (*) (ZeroLC R)) . v = (ZeroLC R) . v thus (r (*) (ZeroLC R)) . v = (ZeroLC R) . ((r ") * v) by A1, Def2 .= 0 by RLVECT_2:20 .= (ZeroLC R) . v by RLVECT_2:20 ; ::_thesis: verum end; hence r (*) (ZeroLC R) = ZeroLC R by RLVECT_2:def_9; ::_thesis: verum end; end; end; theorem Th27: :: RLAFFIN1:27 for r, s being Real for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR being Linear_Combination of R holds r (*) (s (*) LR) = (r * s) (*) LR proof let r, s be Real; ::_thesis: for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR being Linear_Combination of R holds r (*) (s (*) LR) = (r * s) (*) LR let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: for LR being Linear_Combination of R holds r (*) (s (*) LR) = (r * s) (*) LR let LR be Linear_Combination of R; ::_thesis: r (*) (s (*) LR) = (r * s) (*) LR percases ( r = 0 or s = 0 or ( r <> 0 & s <> 0 ) ) ; supposeA1: ( r = 0 or s = 0 ) ; ::_thesis: r (*) (s (*) LR) = (r * s) (*) LR then (r * s) (*) LR = ZeroLC R by Def2; hence r (*) (s (*) LR) = (r * s) (*) LR by A1, Def2, Th26; ::_thesis: verum end; supposeA2: ( r <> 0 & s <> 0 ) ; ::_thesis: r (*) (s (*) LR) = (r * s) (*) LR now__::_thesis:_for_v_being_Element_of_R_holds_(r_(*)_(s_(*)_LR))_._v_=_((r_*_s)_(*)_LR)_._v let v be Element of R; ::_thesis: (r (*) (s (*) LR)) . v = ((r * s) (*) LR) . v thus (r (*) (s (*) LR)) . v = (s (*) LR) . ((r ") * v) by A2, Def2 .= LR . ((s ") * ((r ") * v)) by A2, Def2 .= LR . (((s ") * (r ")) * v) by RLVECT_1:def_7 .= LR . (((r * s) ") * v) by XCMPLX_1:204 .= ((r * s) (*) LR) . v by A2, Def2 ; ::_thesis: verum end; hence r (*) (s (*) LR) = (r * s) (*) LR by RLVECT_2:def_9; ::_thesis: verum end; end; end; theorem Th28: :: RLAFFIN1:28 for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR being Linear_Combination of R holds 1 (*) LR = LR proof let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: for LR being Linear_Combination of R holds 1 (*) LR = LR let LR be Linear_Combination of R; ::_thesis: 1 (*) LR = LR now__::_thesis:_for_v_being_Element_of_R_holds_(1_(*)_LR)_._v_=_LR_._v let v be Element of R; ::_thesis: (1 (*) LR) . v = LR . v thus (1 (*) LR) . v = LR . ((1 ") * v) by Def2 .= LR . v by RLVECT_1:def_8 ; ::_thesis: verum end; hence 1 (*) LR = LR by RLVECT_2:def_9; ::_thesis: verum end; begin definition let S be non empty addLoopStr ; let LS be Linear_Combination of S; func sum LS -> Real means :Def3: :: RLAFFIN1:def 3 ex F being FinSequence of S st ( F is one-to-one & rng F = Carrier LS & it = Sum (LS * F) ); existence ex b1 being Real ex F being FinSequence of S st ( F is one-to-one & rng F = Carrier LS & b1 = Sum (LS * F) ) proof consider p being FinSequence such that A1: rng p = Carrier LS and A2: p is one-to-one by FINSEQ_4:58; reconsider p = p as FinSequence of S by A1, FINSEQ_1:def_4; take Sum (LS * p) ; ::_thesis: ex F being FinSequence of S st ( F is one-to-one & rng F = Carrier LS & Sum (LS * p) = Sum (LS * F) ) thus ex F being FinSequence of S st ( F is one-to-one & rng F = Carrier LS & Sum (LS * p) = Sum (LS * F) ) by A1, A2; ::_thesis: verum end; uniqueness for b1, b2 being Real st ex F being FinSequence of S st ( F is one-to-one & rng F = Carrier LS & b1 = Sum (LS * F) ) & ex F being FinSequence of S st ( F is one-to-one & rng F = Carrier LS & b2 = Sum (LS * F) ) holds b1 = b2 proof let S1, S2 be Real; ::_thesis: ( ex F being FinSequence of S st ( F is one-to-one & rng F = Carrier LS & S1 = Sum (LS * F) ) & ex F being FinSequence of S st ( F is one-to-one & rng F = Carrier LS & S2 = Sum (LS * F) ) implies S1 = S2 ) given F1 being FinSequence of S such that A3: F1 is one-to-one and A4: rng F1 = Carrier LS and A5: S1 = Sum (LS * F1) ; ::_thesis: ( for F being FinSequence of S holds ( not F is one-to-one or not rng F = Carrier LS or not S2 = Sum (LS * F) ) or S1 = S2 ) A6: dom (F1 ") = Carrier LS by A3, A4, FUNCT_1:33; A7: len F1 = card (Carrier LS) by A3, A4, FINSEQ_4:62; given F2 being FinSequence of S such that A8: F2 is one-to-one and A9: rng F2 = Carrier LS and A10: S2 = Sum (LS * F2) ; ::_thesis: S1 = S2 set F12 = (F1 ") * F2; ( dom F2 = Seg (len F2) & len F2 = card (Carrier LS) ) by A8, A9, FINSEQ_1:def_3, FINSEQ_4:62; then A11: dom ((F1 ") * F2) = Seg (len F1) by A6, A7, A9, RELAT_1:27; dom F1 = Seg (len F1) by FINSEQ_1:def_3; then rng (F1 ") = Seg (len F1) by A3, FUNCT_1:33; then A12: rng ((F1 ") * F2) = Seg (len F1) by A6, A9, RELAT_1:28; then reconsider F12 = (F1 ") * F2 as Function of (Seg (len F1)),(Seg (len F1)) by A11, FUNCT_2:1; A13: F12 is onto by A12, FUNCT_2:def_3; len (LS * F1) = len F1 by FINSEQ_2:33; then dom (LS * F1) = Seg (len F1) by FINSEQ_1:def_3; then reconsider F12 = F12 as Permutation of (dom (LS * F1)) by A3, A8, A13; (LS * F1) * F12 = LS * (F1 * F12) by RELAT_1:36 .= LS * ((F1 * (F1 ")) * F2) by RELAT_1:36 .= LS * ((id (Carrier LS)) * F2) by A3, A4, FUNCT_1:39 .= LS * F2 by A9, RELAT_1:53 ; hence S1 = S2 by A5, A10, FINSOP_1:7; ::_thesis: verum end; end; :: deftheorem Def3 defines sum RLAFFIN1:def_3_:_ for S being non empty addLoopStr for LS being Linear_Combination of S for b3 being Real holds ( b3 = sum LS iff ex F being FinSequence of S st ( F is one-to-one & rng F = Carrier LS & b3 = Sum (LS * F) ) ); theorem Th29: :: RLAFFIN1:29 for S being non empty addLoopStr for LS being Linear_Combination of S for F being FinSequence of S st Carrier LS misses rng F holds Sum (LS * F) = 0 proof let S be non empty addLoopStr ; ::_thesis: for LS being Linear_Combination of S for F being FinSequence of S st Carrier LS misses rng F holds Sum (LS * F) = 0 let LS be Linear_Combination of S; ::_thesis: for F being FinSequence of S st Carrier LS misses rng F holds Sum (LS * F) = 0 let F be FinSequence of S; ::_thesis: ( Carrier LS misses rng F implies Sum (LS * F) = 0 ) assume A1: Carrier LS misses rng F ; ::_thesis: Sum (LS * F) = 0 set LF = LS * F; set LF0 = (len (LS * F)) |-> 0; A2: now__::_thesis:_for_k_being_Nat_st_1_<=_k_&_k_<=_len_(LS_*_F)_holds_ (LS_*_F)_._k_=_((len_(LS_*_F))_|->_0)_._k let k be Nat; ::_thesis: ( 1 <= k & k <= len (LS * F) implies (LS * F) . k = ((len (LS * F)) |-> 0) . k ) assume A3: ( 1 <= k & k <= len (LS * F) ) ; ::_thesis: (LS * F) . k = ((len (LS * F)) |-> 0) . k A4: k in dom (LS * F) by A3, FINSEQ_3:25; then k in dom F by FUNCT_1:11; then F . k in rng F by FUNCT_1:def_3; then A5: ( dom LS = the carrier of S & not F . k in Carrier LS ) by A1, FUNCT_2:def_1, XBOOLE_0:3; ( (LS * F) . k = LS . (F . k) & F . k in dom LS ) by A4, FUNCT_1:11, FUNCT_1:12; hence (LS * F) . k = ((len (LS * F)) |-> 0) . k by A5; ::_thesis: verum end; len ((len (LS * F)) |-> 0) = len (LS * F) by CARD_1:def_7; then LS * F = (len (LS * F)) |-> 0 by A2, FINSEQ_1:14; hence Sum (LS * F) = 0 by RVSUM_1:81; ::_thesis: verum end; theorem Th30: :: RLAFFIN1:30 for S being non empty addLoopStr for LS being Linear_Combination of S for F being FinSequence of S st F is one-to-one & Carrier LS c= rng F holds sum LS = Sum (LS * F) proof let S be non empty addLoopStr ; ::_thesis: for LS being Linear_Combination of S for F being FinSequence of S st F is one-to-one & Carrier LS c= rng F holds sum LS = Sum (LS * F) let LS be Linear_Combination of S; ::_thesis: for F being FinSequence of S st F is one-to-one & Carrier LS c= rng F holds sum LS = Sum (LS * F) let F be FinSequence of S; ::_thesis: ( F is one-to-one & Carrier LS c= rng F implies sum LS = Sum (LS * F) ) assume that A1: F is one-to-one and A2: Carrier LS c= rng F ; ::_thesis: sum LS = Sum (LS * F) consider G being FinSequence of S such that A3: G is one-to-one and A4: rng G = Carrier LS and A5: sum LS = Sum (LS * G) by Def3; reconsider R = rng G as Subset of (rng F) by A2, A4; reconsider FR = F - R, FR1 = F - (R `) as FinSequence of S by FINSEQ_3:86; consider p being Permutation of (dom F) such that A6: F * p = (F - (R `)) ^ (F - R) by FINSEQ_3:115; (rng F) \ (R `) = (R `) ` .= R ; then A7: rng FR1 = R by FINSEQ_3:65; FR1 is one-to-one by A1, FINSEQ_3:87; then FR1,G are_fiberwise_equipotent by A3, A7, RFINSEQ:26; then consider q being Permutation of (dom G) such that A8: FR1 = G * q by RFINSEQ:4; len (LS * G) = len G by FINSEQ_2:33; then A9: dom G = dom (LS * G) by FINSEQ_3:29; (LS * G) * q = LS * FR1 by A8, RELAT_1:36; then A10: sum LS = Sum (LS * FR1) by A5, A9, FINSOP_1:7; len (LS * F) = len F by FINSEQ_2:33; then A11: dom F = dom (LS * F) by FINSEQ_3:29; (rng F) \ R = rng FR by FINSEQ_3:65; then rng FR misses Carrier LS by A4, XBOOLE_1:79; then A12: ( LS * (FR1 ^ FR) = (LS * FR1) ^ (LS * FR) & Sum (LS * FR) = 0 ) by Th29, FINSEQOP:9; (LS * F) * p = LS * (FR1 ^ FR) by A6, RELAT_1:36; hence Sum (LS * F) = Sum (LS * (FR1 ^ FR)) by A11, FINSOP_1:7 .= (sum LS) + 0 by A10, A12, RVSUM_1:75 .= sum LS ; ::_thesis: verum end; theorem Th31: :: RLAFFIN1:31 for S being non empty addLoopStr holds sum (ZeroLC S) = 0 proof let S be non empty addLoopStr ; ::_thesis: sum (ZeroLC S) = 0 consider F being FinSequence of S such that F is one-to-one and A1: rng F = Carrier (ZeroLC S) and A2: sum (ZeroLC S) = Sum ((ZeroLC S) * F) by Def3; F = {} by A1, RLVECT_2:def_5; hence sum (ZeroLC S) = 0 by A2, RVSUM_1:72; ::_thesis: verum end; theorem Th32: :: RLAFFIN1:32 for S being non empty addLoopStr for LS being Linear_Combination of S for v being Element of S st Carrier LS c= {v} holds sum LS = LS . v proof let S be non empty addLoopStr ; ::_thesis: for LS being Linear_Combination of S for v being Element of S st Carrier LS c= {v} holds sum LS = LS . v let LS be Linear_Combination of S; ::_thesis: for v being Element of S st Carrier LS c= {v} holds sum LS = LS . v let v be Element of S; ::_thesis: ( Carrier LS c= {v} implies sum LS = LS . v ) consider p being FinSequence such that A1: rng p = {v} and A2: p is one-to-one by FINSEQ_4:58; reconsider p = p as FinSequence of S by A1, FINSEQ_1:def_4; ( dom LS = the carrier of S & p = <*v*> ) by A1, A2, FINSEQ_3:97, FUNCT_2:def_1; then A3: LS * p = <*(LS . v)*> by FINSEQ_2:34; assume Carrier LS c= {v} ; ::_thesis: sum LS = LS . v hence sum LS = Sum (LS * p) by A1, A2, Th30 .= LS . v by A3, RVSUM_1:73 ; ::_thesis: verum end; theorem :: RLAFFIN1:33 for S being non empty addLoopStr for LS being Linear_Combination of S for v1, v2 being Element of S st Carrier LS c= {v1,v2} & v1 <> v2 holds sum LS = (LS . v1) + (LS . v2) proof let S be non empty addLoopStr ; ::_thesis: for LS being Linear_Combination of S for v1, v2 being Element of S st Carrier LS c= {v1,v2} & v1 <> v2 holds sum LS = (LS . v1) + (LS . v2) let LS be Linear_Combination of S; ::_thesis: for v1, v2 being Element of S st Carrier LS c= {v1,v2} & v1 <> v2 holds sum LS = (LS . v1) + (LS . v2) let v1, v2 be Element of S; ::_thesis: ( Carrier LS c= {v1,v2} & v1 <> v2 implies sum LS = (LS . v1) + (LS . v2) ) consider p being FinSequence such that A1: rng p = {v1,v2} and A2: p is one-to-one by FINSEQ_4:58; reconsider p = p as FinSequence of S by A1, FINSEQ_1:def_4; assume that A3: Carrier LS c= {v1,v2} and A4: v1 <> v2 ; ::_thesis: sum LS = (LS . v1) + (LS . v2) A5: dom LS = the carrier of S by FUNCT_2:def_1; A6: Sum <*(LS . v1)*> = LS . v1 by RVSUM_1:73; ( p = <*v1,v2*> or p = <*v2,v1*> ) by A1, A2, A4, FINSEQ_3:99; then ( LS * p = <*(LS . v1),(LS . v2)*> or LS * p = <*(LS . v2),(LS . v1)*> ) by A5, FINSEQ_2:125; then ( Sum (LS * p) = (LS . v1) + (LS . v2) or Sum (LS * p) = (LS . v2) + (LS . v1) ) by A6, RVSUM_1:74, RVSUM_1:76; hence sum LS = (LS . v1) + (LS . v2) by A1, A2, A3, Th30; ::_thesis: verum end; theorem Th34: :: RLAFFIN1:34 for S being non empty addLoopStr for LS1, LS2 being Linear_Combination of S holds sum (LS1 + LS2) = (sum LS1) + (sum LS2) proof let S be non empty addLoopStr ; ::_thesis: for LS1, LS2 being Linear_Combination of S holds sum (LS1 + LS2) = (sum LS1) + (sum LS2) let LS1, LS2 be Linear_Combination of S; ::_thesis: sum (LS1 + LS2) = (sum LS1) + (sum LS2) set C1 = Carrier LS1; set C2 = Carrier LS2; consider p112 being FinSequence such that A1: rng p112 = (Carrier LS1) \ (Carrier LS2) and A2: p112 is one-to-one by FINSEQ_4:58; consider p12 being FinSequence such that A3: rng p12 = (Carrier LS1) /\ (Carrier LS2) and A4: p12 is one-to-one by FINSEQ_4:58; consider p211 being FinSequence such that A5: rng p211 = (Carrier LS2) \ (Carrier LS1) and A6: p211 is one-to-one by FINSEQ_4:58; reconsider p112 = p112, p12 = p12, p211 = p211 as FinSequence of S by A1, A3, A5, FINSEQ_1:def_4; (Carrier LS1) \ (Carrier LS2) misses (Carrier LS1) /\ (Carrier LS2) by XBOOLE_1:89; then A7: p112 ^ p12 is one-to-one by A1, A2, A3, A4, FINSEQ_3:91; set p1 = p112 ^ p12; A8: rng (p112 ^ p12) = ((Carrier LS1) \ (Carrier LS2)) \/ ((Carrier LS1) /\ (Carrier LS2)) by A1, A3, FINSEQ_1:31 .= Carrier LS1 by XBOOLE_1:51 ; then A9: rng ((p112 ^ p12) ^ p211) = (Carrier LS1) \/ ((Carrier LS2) \ (Carrier LS1)) by A5, FINSEQ_1:31 .= (Carrier LS1) \/ (Carrier LS2) by XBOOLE_1:39 ; set p2 = p12 ^ p211; A10: rng (p12 ^ p211) = ((Carrier LS1) /\ (Carrier LS2)) \/ ((Carrier LS2) \ (Carrier LS1)) by A3, A5, FINSEQ_1:31 .= Carrier LS2 by XBOOLE_1:51 ; set pp = (p112 ^ p12) ^ p211; (p112 ^ p12) ^ p211 = p112 ^ (p12 ^ p211) by FINSEQ_1:32; then A11: LS2 * ((p112 ^ p12) ^ p211) = (LS2 * p112) ^ (LS2 * (p12 ^ p211)) by FINSEQOP:9; (Carrier LS2) \ (Carrier LS1) misses (Carrier LS1) /\ (Carrier LS2) by XBOOLE_1:89; then A12: p12 ^ p211 is one-to-one by A3, A4, A5, A6, FINSEQ_3:91; Carrier LS2 misses (Carrier LS1) \ (Carrier LS2) by XBOOLE_1:79; then Sum (LS2 * p112) = 0 by A1, Th29; then A13: Sum (LS2 * ((p112 ^ p12) ^ p211)) = 0 + (Sum (LS2 * (p12 ^ p211))) by A11, RVSUM_1:75 .= sum LS2 by A10, A12, Def3 ; ( len (LS1 * ((p112 ^ p12) ^ p211)) = len ((p112 ^ p12) ^ p211) & len (LS2 * ((p112 ^ p12) ^ p211)) = len ((p112 ^ p12) ^ p211) ) by FINSEQ_2:33; then reconsider L1p = LS1 * ((p112 ^ p12) ^ p211), L2p = LS2 * ((p112 ^ p12) ^ p211) as Element of (len ((p112 ^ p12) ^ p211)) -tuples_on REAL by FINSEQ_2:92; A14: (LS1 + LS2) * ((p112 ^ p12) ^ p211) = L1p + L2p by Th13; A15: Carrier LS1 misses (Carrier LS2) \ (Carrier LS1) by XBOOLE_1:79; then ( LS1 * ((p112 ^ p12) ^ p211) = (LS1 * (p112 ^ p12)) ^ (LS1 * p211) & Sum (LS1 * p211) = 0 ) by A5, Th29, FINSEQOP:9; then A16: Sum (LS1 * ((p112 ^ p12) ^ p211)) = (Sum (LS1 * (p112 ^ p12))) + 0 by RVSUM_1:75 .= sum LS1 by A7, A8, Def3 ; A17: Carrier (LS1 + LS2) c= (Carrier LS1) \/ (Carrier LS2) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Carrier (LS1 + LS2) or x in (Carrier LS1) \/ (Carrier LS2) ) assume x in Carrier (LS1 + LS2) ; ::_thesis: x in (Carrier LS1) \/ (Carrier LS2) then consider u being Element of S such that A18: x = u and A19: (LS1 + LS2) . u <> 0 ; (LS1 + LS2) . u = (LS1 . u) + (LS2 . u) by RLVECT_2:def_10; then ( LS1 . u <> 0 or LS2 . u <> 0 ) by A19; then ( x in Carrier LS1 or x in Carrier LS2 ) by A18; hence x in (Carrier LS1) \/ (Carrier LS2) by XBOOLE_0:def_3; ::_thesis: verum end; (p112 ^ p12) ^ p211 is one-to-one by A5, A6, A7, A8, A15, FINSEQ_3:91; hence sum (LS1 + LS2) = Sum (L1p + L2p) by A9, A14, A17, Th30 .= (sum LS1) + (sum LS2) by A13, A16, RVSUM_1:89 ; ::_thesis: verum end; theorem Th35: :: RLAFFIN1:35 for r being Real for V being RealLinearSpace for L being Linear_Combination of V holds sum (r * L) = r * (sum L) proof let r be Real; ::_thesis: for V being RealLinearSpace for L being Linear_Combination of V holds sum (r * L) = r * (sum L) let V be RealLinearSpace; ::_thesis: for L being Linear_Combination of V holds sum (r * L) = r * (sum L) let L be Linear_Combination of V; ::_thesis: sum (r * L) = r * (sum L) consider F being FinSequence of V such that A1: F is one-to-one and A2: rng F = Carrier L and A3: sum L = Sum (L * F) by Def3; L is Linear_Combination of Carrier L by RLVECT_2:def_6; then r * L is Linear_Combination of Carrier L by RLVECT_2:44; then A4: Carrier (r * L) c= rng F by A2, RLVECT_2:def_6; thus r * (sum L) = Sum (r * (L * F)) by A3, RVSUM_1:87 .= Sum ((r * L) * F) by Th14 .= sum (r * L) by A1, A4, Th30 ; ::_thesis: verum end; theorem Th36: :: RLAFFIN1:36 for V being RealLinearSpace for L1, L2 being Linear_Combination of V holds sum (L1 - L2) = (sum L1) - (sum L2) proof let V be RealLinearSpace; ::_thesis: for L1, L2 being Linear_Combination of V holds sum (L1 - L2) = (sum L1) - (sum L2) let L1, L2 be Linear_Combination of V; ::_thesis: sum (L1 - L2) = (sum L1) - (sum L2) thus sum (L1 - L2) = (sum L1) + (sum ((- 1) * L2)) by Th34 .= (sum L1) + ((- 1) * (sum L2)) by Th35 .= (sum L1) - (sum L2) ; ::_thesis: verum end; theorem Th37: :: RLAFFIN1:37 for G being non empty right_complementable Abelian add-associative right_zeroed addLoopStr for LG being Linear_Combination of G for g being Element of G holds sum LG = sum (g + LG) proof let G be non empty right_complementable Abelian add-associative right_zeroed addLoopStr ; ::_thesis: for LG being Linear_Combination of G for g being Element of G holds sum LG = sum (g + LG) let LG be Linear_Combination of G; ::_thesis: for g being Element of G holds sum LG = sum (g + LG) let g be Element of G; ::_thesis: sum LG = sum (g + LG) set gL = g + LG; deffunc H1( Element of G) -> Element of the carrier of G = $1 + g; consider f being Function of the carrier of G, the carrier of G such that A1: for h being Element of G holds f . h = H1(h) from FUNCT_2:sch_4(); consider F being FinSequence of G such that A2: F is one-to-one and A3: rng F = Carrier LG and A4: sum LG = Sum (LG * F) by Def3; A5: len (f * F) = len F by FINSEQ_2:33; A6: len (LG * F) = len F by FINSEQ_2:33; A7: len ((g + LG) * (f * F)) = len (f * F) by FINSEQ_2:33; A8: now__::_thesis:_for_k_being_Nat_st_1_<=_k_&_k_<=_len_F_holds_ ((g_+_LG)_*_(f_*_F))_._k_=_(LG_*_F)_._k let k be Nat; ::_thesis: ( 1 <= k & k <= len F implies ((g + LG) * (f * F)) . k = (LG * F) . k ) assume A9: ( 1 <= k & k <= len F ) ; ::_thesis: ((g + LG) * (f * F)) . k = (LG * F) . k then k in dom F by FINSEQ_3:25; then A10: F /. k = F . k by PARTFUN1:def_6; k in dom (LG * F) by A6, A9, FINSEQ_3:25; then A11: (LG * F) . k = LG . (F . k) by FUNCT_1:12; k in dom ((g + LG) * (f * F)) by A5, A7, A9, FINSEQ_3:25; then A12: ((g + LG) * (f * F)) . k = (g + LG) . ((f * F) . k) by FUNCT_1:12; k in dom (f * F) by A5, A9, FINSEQ_3:25; then (f * F) . k = f . (F . k) by FUNCT_1:12; then (f * F) . k = (F /. k) + g by A1, A10; hence ((g + LG) * (f * F)) . k = LG . (((F /. k) + g) - g) by A12, Def1 .= LG . (((F /. k) + g) + (- g)) by RLVECT_1:def_11 .= LG . ((F /. k) + (g + (- g))) by RLVECT_1:def_3 .= LG . ((F /. k) + (0. G)) by RLVECT_1:def_10 .= (LG * F) . k by A10, A11, RLVECT_1:4 ; ::_thesis: verum end; now__::_thesis:_for_x1,_x2_being_set_st_x1_in_dom_(f_*_F)_&_x2_in_dom_(f_*_F)_&_(f_*_F)_._x1_=_(f_*_F)_._x2_holds_ x1_=_x2 let x1, x2 be set ; ::_thesis: ( x1 in dom (f * F) & x2 in dom (f * F) & (f * F) . x1 = (f * F) . x2 implies x1 = x2 ) assume that A13: x1 in dom (f * F) and A14: x2 in dom (f * F) and A15: (f * F) . x1 = (f * F) . x2 ; ::_thesis: x1 = x2 A16: f . (F /. x1) = (F /. x1) + g by A1; A17: x1 in dom F by A13, FUNCT_1:11; then A18: F . x1 = F /. x1 by PARTFUN1:def_6; A19: x2 in dom F by A14, FUNCT_1:11; then A20: F . x2 = F /. x2 by PARTFUN1:def_6; ( (f * F) . x1 = f . (F . x1) & (f * F) . x2 = f . (F . x2) ) by A13, A14, FUNCT_1:12; then (F /. x1) + g = (F /. x2) + g by A1, A15, A16, A18, A20; then F /. x1 = F /. x2 by RLVECT_1:8; hence x1 = x2 by A2, A17, A18, A19, A20, FUNCT_1:def_4; ::_thesis: verum end; then A21: f * F is one-to-one by FUNCT_1:def_4; Carrier (g + LG) c= rng (f * F) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Carrier (g + LG) or x in rng (f * F) ) assume x in Carrier (g + LG) ; ::_thesis: x in rng (f * F) then x in g + (Carrier LG) by Th16; then consider h being Element of G such that A22: x = g + h and A23: h in Carrier LG ; consider y being set such that A24: y in dom F and A25: F . y = h by A3, A23, FUNCT_1:def_3; A26: f . (F . y) = x by A1, A22, A25; dom f = the carrier of G by FUNCT_2:def_1; then A27: y in dom (f * F) by A24, A25, FUNCT_1:11; then (f * F) . y in rng (f * F) by FUNCT_1:def_3; hence x in rng (f * F) by A26, A27, FUNCT_1:12; ::_thesis: verum end; then sum (g + LG) = Sum ((g + LG) * (f * F)) by A21, Th30; hence sum LG = sum (g + LG) by A4, A5, A6, A7, A8, FINSEQ_1:14; ::_thesis: verum end; theorem Th38: :: RLAFFIN1:38 for r being Real for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR being Linear_Combination of R st r <> 0 holds sum LR = sum (r (*) LR) proof let r be Real; ::_thesis: for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for LR being Linear_Combination of R st r <> 0 holds sum LR = sum (r (*) LR) let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: for LR being Linear_Combination of R st r <> 0 holds sum LR = sum (r (*) LR) let LR be Linear_Combination of R; ::_thesis: ( r <> 0 implies sum LR = sum (r (*) LR) ) set rL = r (*) LR; deffunc H1( Element of R) -> Element of the carrier of R = r * $1; consider f being Function of the carrier of R, the carrier of R such that A1: for v being Element of R holds f . v = H1(v) from FUNCT_2:sch_4(); consider F being FinSequence of R such that A2: F is one-to-one and A3: rng F = Carrier LR and A4: sum LR = Sum (LR * F) by Def3; assume A5: r <> 0 ; ::_thesis: sum LR = sum (r (*) LR) now__::_thesis:_for_x1,_x2_being_set_st_x1_in_dom_(f_*_F)_&_x2_in_dom_(f_*_F)_&_(f_*_F)_._x1_=_(f_*_F)_._x2_holds_ x1_=_x2 let x1, x2 be set ; ::_thesis: ( x1 in dom (f * F) & x2 in dom (f * F) & (f * F) . x1 = (f * F) . x2 implies x1 = x2 ) assume that A6: x1 in dom (f * F) and A7: x2 in dom (f * F) and A8: (f * F) . x1 = (f * F) . x2 ; ::_thesis: x1 = x2 A9: f . (F /. x1) = r * (F /. x1) by A1; A10: x1 in dom F by A6, FUNCT_1:11; then A11: F . x1 = F /. x1 by PARTFUN1:def_6; A12: x2 in dom F by A7, FUNCT_1:11; then A13: F . x2 = F /. x2 by PARTFUN1:def_6; ( (f * F) . x1 = f . (F . x1) & (f * F) . x2 = f . (F . x2) ) by A6, A7, FUNCT_1:12; then A14: r * (F /. x1) = r * (F /. x2) by A1, A8, A9, A11, A13; F /. x1 = 1 * (F /. x1) by RLVECT_1:def_8 .= ((r ") * r) * (F /. x1) by A5, XCMPLX_0:def_7 .= (r ") * (r * (F /. x2)) by A14, RLVECT_1:def_7 .= ((r ") * r) * (F /. x2) by RLVECT_1:def_7 .= 1 * (F /. x2) by A5, XCMPLX_0:def_7 .= F /. x2 by RLVECT_1:def_8 ; hence x1 = x2 by A2, A10, A11, A12, A13, FUNCT_1:def_4; ::_thesis: verum end; then A15: f * F is one-to-one by FUNCT_1:def_4; A16: len (LR * F) = len F by FINSEQ_2:33; A17: len (f * F) = len F by FINSEQ_2:33; A18: len ((r (*) LR) * (f * F)) = len (f * F) by FINSEQ_2:33; now__::_thesis:_for_k_being_Nat_st_1_<=_k_&_k_<=_len_F_holds_ ((r_(*)_LR)_*_(f_*_F))_._k_=_(LR_*_F)_._k let k be Nat; ::_thesis: ( 1 <= k & k <= len F implies ((r (*) LR) * (f * F)) . k = (LR * F) . k ) assume A19: ( 1 <= k & k <= len F ) ; ::_thesis: ((r (*) LR) * (f * F)) . k = (LR * F) . k then k in dom F by FINSEQ_3:25; then A20: F /. k = F . k by PARTFUN1:def_6; k in dom (LR * F) by A16, A19, FINSEQ_3:25; then A21: (LR * F) . k = LR . (F . k) by FUNCT_1:12; k in dom (f * F) by A17, A19, FINSEQ_3:25; then A22: (f * F) . k = f . (F . k) by FUNCT_1:12; k in dom ((r (*) LR) * (f * F)) by A17, A18, A19, FINSEQ_3:25; then ((r (*) LR) * (f * F)) . k = (r (*) LR) . ((f * F) . k) by FUNCT_1:12; hence ((r (*) LR) * (f * F)) . k = (r (*) LR) . (r * (F /. k)) by A1, A20, A22 .= LR . ((r ") * (r * (F /. k))) by A5, Def2 .= LR . (((r ") * r) * (F /. k)) by RLVECT_1:def_7 .= LR . (1 * (F /. k)) by A5, XCMPLX_0:def_7 .= (LR * F) . k by A20, A21, RLVECT_1:def_8 ; ::_thesis: verum end; then A23: LR * F = (r (*) LR) * (f * F) by A16, A17, A18, FINSEQ_1:14; Carrier (r (*) LR) c= rng (f * F) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Carrier (r (*) LR) or x in rng (f * F) ) assume x in Carrier (r (*) LR) ; ::_thesis: x in rng (f * F) then x in r * (Carrier LR) by A5, Th23; then consider v being Element of R such that A24: x = r * v and A25: v in Carrier LR ; consider y being set such that A26: y in dom F and A27: F . y = v by A3, A25, FUNCT_1:def_3; A28: f . v = x by A1, A24; A29: dom F = dom (f * F) by A17, FINSEQ_3:29; then (f * F) . y = f . v by A26, A27, FUNCT_1:12; hence x in rng (f * F) by A26, A28, A29, FUNCT_1:def_3; ::_thesis: verum end; hence sum LR = sum (r (*) LR) by A4, A15, A23, Th30; ::_thesis: verum end; theorem Th39: :: RLAFFIN1:39 for V being RealLinearSpace for v being VECTOR of V for L being Linear_Combination of V holds Sum (v + L) = ((sum L) * v) + (Sum L) proof let V be RealLinearSpace; ::_thesis: for v being VECTOR of V for L being Linear_Combination of V holds Sum (v + L) = ((sum L) * v) + (Sum L) let v be VECTOR of V; ::_thesis: for L being Linear_Combination of V holds Sum (v + L) = ((sum L) * v) + (Sum L) let L be Linear_Combination of V; ::_thesis: Sum (v + L) = ((sum L) * v) + (Sum L) defpred S1[ Nat] means for L being Linear_Combination of V st card (Carrier L) <= $1 holds Sum (v + L) = ((sum L) * v) + (Sum L); A1: for n being Nat st S1[n] holds S1[n + 1] proof let n be Nat; ::_thesis: ( S1[n] implies S1[n + 1] ) assume A2: S1[n] ; ::_thesis: S1[n + 1] let L be Linear_Combination of V; ::_thesis: ( card (Carrier L) <= n + 1 implies Sum (v + L) = ((sum L) * v) + (Sum L) ) assume A3: card (Carrier L) <= n + 1 ; ::_thesis: Sum (v + L) = ((sum L) * v) + (Sum L) percases ( card (Carrier L) <= n or card (Carrier L) = n + 1 ) by A3, NAT_1:8; suppose card (Carrier L) <= n ; ::_thesis: Sum (v + L) = ((sum L) * v) + (Sum L) hence Sum (v + L) = ((sum L) * v) + (Sum L) by A2; ::_thesis: verum end; supposeA4: card (Carrier L) = n + 1 ; ::_thesis: Sum (v + L) = ((sum L) * v) + (Sum L) then not Carrier L is empty ; then consider w being set such that A5: w in Carrier L by XBOOLE_0:def_1; reconsider w = w as Element of V by A5; A6: card ((Carrier L) \ {w}) = n by A4, A5, STIRL2_1:55; consider Lw being Linear_Combination of {w} such that A7: Lw . w = L . w by RLVECT_4:37; set LLw = L - Lw; (L - Lw) . w = (L . w) - (Lw . w) by RLVECT_2:54 .= 0 by A7 ; then A8: not w in Carrier (L - Lw) by RLVECT_2:19; A9: Carrier Lw c= {w} by RLVECT_2:def_6; then A10: ( Carrier (L - Lw) c= (Carrier L) \/ (Carrier Lw) & (Carrier L) \/ (Carrier Lw) c= (Carrier L) \/ {w} ) by RLVECT_2:55, XBOOLE_1:9; (Carrier L) \/ {w} = Carrier L by A5, ZFMISC_1:40; then Carrier (L - Lw) c= Carrier L by A10, XBOOLE_1:1; then card (Carrier (L - Lw)) <= n by A8, A6, NAT_1:43, ZFMISC_1:34; then A11: Sum (v + (L - Lw)) = ((sum (L - Lw)) * v) + (Sum (L - Lw)) by A2; A12: (L - Lw) + Lw = L + (Lw - Lw) by RLVECT_2:40 .= L + (ZeroLC V) by RLVECT_2:57 .= L by RLVECT_2:41 ; then A13: Sum L = (Sum (L - Lw)) + (Sum Lw) by RLVECT_3:1 .= (Sum (L - Lw)) + ((Lw . w) * w) by RLVECT_2:32 ; v + (Carrier Lw) c= v + {w} by A9, RLTOPSP1:8; then v + (Carrier Lw) c= {(v + w)} by Lm3; then Carrier (v + Lw) c= {(v + w)} by Th16; then v + Lw is Linear_Combination of {(v + w)} by RLVECT_2:def_6; then A14: Sum (v + Lw) = ((v + Lw) . (v + w)) * (v + w) by RLVECT_2:32 .= (Lw . ((v + w) - v)) * (v + w) by Def1 .= (Lw . w) * (v + w) by RLVECT_4:1 ; A15: sum L = (sum (L - Lw)) + (sum Lw) by A12, Th34 .= (sum (L - Lw)) + (Lw . w) by A9, Th32 ; v + L = (v + (L - Lw)) + (v + Lw) by A12, Th17; hence Sum (v + L) = (Sum (v + (L - Lw))) + (Sum (v + Lw)) by RLVECT_3:1 .= (((sum (L - Lw)) * v) + (Sum (L - Lw))) + (((Lw . w) * v) + ((Lw . w) * w)) by A11, A14, RLVECT_1:def_5 .= ((((sum (L - Lw)) * v) + (Sum (L - Lw))) + ((Lw . w) * v)) + ((Lw . w) * w) by RLVECT_1:def_3 .= ((((sum (L - Lw)) * v) + ((Lw . w) * v)) + (Sum (L - Lw))) + ((Lw . w) * w) by RLVECT_1:def_3 .= (((sum L) * v) + (Sum (L - Lw))) + ((Lw . w) * w) by A15, RLVECT_1:def_6 .= ((sum L) * v) + (Sum L) by A13, RLVECT_1:def_3 ; ::_thesis: verum end; end; end; A16: S1[ 0 ] proof let L be Linear_Combination of V; ::_thesis: ( card (Carrier L) <= 0 implies Sum (v + L) = ((sum L) * v) + (Sum L) ) assume card (Carrier L) <= 0 ; ::_thesis: Sum (v + L) = ((sum L) * v) + (Sum L) then A17: Carrier L = {} V ; then A18: ( L = ZeroLC V & Sum L = 0. V ) by RLVECT_2:34, RLVECT_2:def_5; v + (Carrier L) = {} by A17, Th8; then Carrier (v + L) = {} by Th16; hence Sum (v + L) = 0. V by RLVECT_2:34 .= (0. V) + (0. V) by RLVECT_1:4 .= ((sum L) * v) + (Sum L) by A18, Th31, RLVECT_1:10 ; ::_thesis: verum end; for n being Nat holds S1[n] from NAT_1:sch_2(A16, A1); then S1[ card (Carrier L)] ; hence Sum (v + L) = ((sum L) * v) + (Sum L) ; ::_thesis: verum end; theorem Th40: :: RLAFFIN1:40 for r being Real for V being RealLinearSpace for L being Linear_Combination of V holds Sum (r (*) L) = r * (Sum L) proof let r be Real; ::_thesis: for V being RealLinearSpace for L being Linear_Combination of V holds Sum (r (*) L) = r * (Sum L) let V be RealLinearSpace; ::_thesis: for L being Linear_Combination of V holds Sum (r (*) L) = r * (Sum L) let L be Linear_Combination of V; ::_thesis: Sum (r (*) L) = r * (Sum L) defpred S1[ Nat] means for L being Linear_Combination of V st card (Carrier L) <= $1 holds Sum (r (*) L) = r * (Sum L); A1: for n being Nat st S1[n] holds S1[n + 1] proof let n be Nat; ::_thesis: ( S1[n] implies S1[n + 1] ) assume A2: S1[n] ; ::_thesis: S1[n + 1] let L be Linear_Combination of V; ::_thesis: ( card (Carrier L) <= n + 1 implies Sum (r (*) L) = r * (Sum L) ) assume A3: card (Carrier L) <= n + 1 ; ::_thesis: Sum (r (*) L) = r * (Sum L) percases ( r = 0 or r <> 0 ) ; suppose r = 0 ; ::_thesis: Sum (r (*) L) = r * (Sum L) then ( r (*) L = ZeroLC V & r * (Sum L) = 0. V ) by Def2, RLVECT_1:10; hence Sum (r (*) L) = r * (Sum L) by RLVECT_2:30; ::_thesis: verum end; supposeA4: r <> 0 ; ::_thesis: Sum (r (*) L) = r * (Sum L) percases ( card (Carrier L) <= n or card (Carrier L) = n + 1 ) by A3, NAT_1:8; suppose card (Carrier L) <= n ; ::_thesis: Sum (r (*) L) = r * (Sum L) hence Sum (r (*) L) = r * (Sum L) by A2; ::_thesis: verum end; supposeA5: card (Carrier L) = n + 1 ; ::_thesis: Sum (r (*) L) = r * (Sum L) then Carrier L <> {} ; then consider p being set such that A6: p in Carrier L by XBOOLE_0:def_1; reconsider p = p as Element of V by A6; A7: card ((Carrier L) \ {p}) = n by A5, A6, STIRL2_1:55; consider Lp being Linear_Combination of {p} such that A8: Lp . p = L . p by RLVECT_4:37; set LLp = L - Lp; (L - Lp) . p = (L . p) - (Lp . p) by RLVECT_2:54 .= 0 by A8 ; then A9: not p in Carrier (L - Lp) by RLVECT_2:19; A10: Carrier Lp c= {p} by RLVECT_2:def_6; then A11: ( Carrier (L - Lp) c= (Carrier L) \/ (Carrier Lp) & (Carrier L) \/ (Carrier Lp) c= (Carrier L) \/ {p} ) by RLVECT_2:55, XBOOLE_1:9; r * (Carrier Lp) c= {(r * p)} proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in r * (Carrier Lp) or x in {(r * p)} ) assume x in r * (Carrier Lp) ; ::_thesis: x in {(r * p)} then consider w being Element of V such that A12: x = r * w and A13: w in Carrier Lp ; w = p by A10, A13, TARSKI:def_1; hence x in {(r * p)} by A12, TARSKI:def_1; ::_thesis: verum end; then Carrier (r (*) Lp) c= {(r * p)} by A4, Th23; then r (*) Lp is Linear_Combination of {(r * p)} by RLVECT_2:def_6; then A14: Sum (r (*) Lp) = ((r (*) Lp) . (r * p)) * (r * p) by RLVECT_2:32 .= (Lp . ((r ") * (r * p))) * (r * p) by A4, Def2 .= (Lp . (((r ") * r) * p)) * (r * p) by RLVECT_1:def_7 .= (Lp . (1 * p)) * (r * p) by A4, XCMPLX_0:def_7 .= (Lp . p) * (r * p) by RLVECT_1:def_8 ; A15: (L - Lp) + Lp = L + (Lp - Lp) by RLVECT_2:40 .= L + (ZeroLC V) by RLVECT_2:57 .= L by RLVECT_2:41 ; then A16: Sum L = (Sum (L - Lp)) + (Sum Lp) by RLVECT_3:1 .= (Sum (L - Lp)) + ((Lp . p) * p) by RLVECT_2:32 ; (Carrier L) \/ {p} = Carrier L by A6, ZFMISC_1:40; then Carrier (L - Lp) c= Carrier L by A11, XBOOLE_1:1; then card (Carrier (L - Lp)) <= n by A9, A7, NAT_1:43, ZFMISC_1:34; then A17: Sum (r (*) (L - Lp)) = r * (Sum (L - Lp)) by A2; r (*) L = (r (*) (L - Lp)) + (r (*) Lp) by A15, Th24; hence Sum (r (*) L) = (Sum (r (*) (L - Lp))) + (Sum (r (*) Lp)) by RLVECT_3:1 .= (r * (Sum (L - Lp))) + (((Lp . p) * r) * p) by A14, A17, RLVECT_1:def_7 .= (r * (Sum (L - Lp))) + (r * ((Lp . p) * p)) by RLVECT_1:def_7 .= r * (Sum L) by A16, RLVECT_1:def_5 ; ::_thesis: verum end; end; end; end; end; A18: S1[ 0 ] proof let L be Linear_Combination of V; ::_thesis: ( card (Carrier L) <= 0 implies Sum (r (*) L) = r * (Sum L) ) assume card (Carrier L) <= 0 ; ::_thesis: Sum (r (*) L) = r * (Sum L) then Carrier L = {} ; then A19: L = ZeroLC V by RLVECT_2:def_5; then ( r * (0. V) = 0. V & Sum L = 0. V ) by RLVECT_1:10, RLVECT_2:30; hence Sum (r (*) L) = r * (Sum L) by A19, Th26; ::_thesis: verum end; for n being Nat holds S1[n] from NAT_1:sch_2(A18, A1); then S1[ card (Carrier L)] ; hence Sum (r (*) L) = r * (Sum L) ; ::_thesis: verum end; begin definition let V be RealLinearSpace; let A be Subset of V; attrA is affinely-independent means :Def4: :: RLAFFIN1:def 4 ( A is empty or ex v being VECTOR of V st ( v in A & ((- v) + A) \ {(0. V)} is linearly-independent ) ); end; :: deftheorem Def4 defines affinely-independent RLAFFIN1:def_4_:_ for V being RealLinearSpace for A being Subset of V holds ( A is affinely-independent iff ( A is empty or ex v being VECTOR of V st ( v in A & ((- v) + A) \ {(0. V)} is linearly-independent ) ) ); registration let V be RealLinearSpace; cluster empty -> affinely-independent for Element of K19( the carrier of V); coherence for b1 being Subset of V st b1 is empty holds b1 is affinely-independent by Def4; let v be VECTOR of V; cluster{v} -> affinely-independent for Subset of V; coherence for b1 being Subset of V st b1 = {v} holds b1 is affinely-independent proof {v} is affinely-independent proof assume not {v} is empty ; :: according to RLAFFIN1:def_4 ::_thesis: ex v being VECTOR of V st ( v in {v} & ((- v) + {v}) \ {(0. V)} is linearly-independent ) take v ; ::_thesis: ( v in {v} & ((- v) + {v}) \ {(0. V)} is linearly-independent ) thus v in {v} by TARSKI:def_1; ::_thesis: ((- v) + {v}) \ {(0. V)} is linearly-independent (- v) + v = 0. V by RLVECT_1:5; then (- v) + {v} = {(0. V)} by Lm3; then ((- v) + {v}) \ {(0. V)} = {} the carrier of V by XBOOLE_1:37; hence ((- v) + {v}) \ {(0. V)} is linearly-independent by RLVECT_3:7; ::_thesis: verum end; hence for b1 being Subset of V st b1 = {v} holds b1 is affinely-independent ; ::_thesis: verum end; let w be VECTOR of V; cluster{v,w} -> affinely-independent for Subset of V; coherence for b1 being Subset of V st b1 = {v,w} holds b1 is affinely-independent proof percases ( v = w or v <> w ) ; suppose v = w ; ::_thesis: for b1 being Subset of V st b1 = {v,w} holds b1 is affinely-independent then {v,w} = {w} by ENUMSET1:29; hence for b1 being Subset of V st b1 = {v,w} holds b1 is affinely-independent ; ::_thesis: verum end; supposeA1: v <> w ; ::_thesis: for b1 being Subset of V st b1 = {v,w} holds b1 is affinely-independent (- v) + {v,w} c= {((- v) + w),(0. V)} proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in (- v) + {v,w} or x in {((- v) + w),(0. V)} ) assume x in (- v) + {v,w} ; ::_thesis: x in {((- v) + w),(0. V)} then consider r being Element of V such that A2: x = (- v) + r and A3: r in {v,w} ; percases ( r = v or r = w ) by A3, TARSKI:def_2; suppose r = v ; ::_thesis: x in {((- v) + w),(0. V)} then x = 0. V by A2, RLVECT_1:5; hence x in {((- v) + w),(0. V)} by TARSKI:def_2; ::_thesis: verum end; suppose r = w ; ::_thesis: x in {((- v) + w),(0. V)} hence x in {((- v) + w),(0. V)} by A2, TARSKI:def_2; ::_thesis: verum end; end; end; then A4: ((- v) + {v,w}) \ {(0. V)} c= {((- v) + w),(0. V)} \ {(0. V)} by XBOOLE_1:33; - (- v) = v by RLVECT_1:17; then A5: w + (- v) <> 0. V by A1, RLVECT_1:6; then A6: {((- v) + w)} is linearly-independent by RLVECT_3:8; {v,w} is affinely-independent proof assume not {v,w} is empty ; :: according to RLAFFIN1:def_4 ::_thesis: ex v being VECTOR of V st ( v in {v,w} & ((- v) + {v,w}) \ {(0. V)} is linearly-independent ) take v ; ::_thesis: ( v in {v,w} & ((- v) + {v,w}) \ {(0. V)} is linearly-independent ) thus v in {v,w} by TARSKI:def_2; ::_thesis: ((- v) + {v,w}) \ {(0. V)} is linearly-independent ( 0. V in {(0. V)} & not (- v) + w in {(0. V)} ) by A5, TARSKI:def_1; then ((- v) + {v,w}) \ {(0. V)} c= {((- v) + w)} by A4, ZFMISC_1:62; hence ((- v) + {v,w}) \ {(0. V)} is linearly-independent by A6, RLVECT_3:5; ::_thesis: verum end; hence for b1 being Subset of V st b1 = {v,w} holds b1 is affinely-independent ; ::_thesis: verum end; end; end; end; registration let V be RealLinearSpace; cluster1 -element affinely-independent for Element of K19( the carrier of V); existence ex b1 being Subset of V st ( b1 is 1 -element & b1 is affinely-independent ) proof take { the Element of V} ; ::_thesis: ( { the Element of V} is 1 -element & { the Element of V} is affinely-independent ) thus ( { the Element of V} is 1 -element & { the Element of V} is affinely-independent ) ; ::_thesis: verum end; end; Lm5: for V being RealLinearSpace for A being Subset of V st A is affinely-independent holds for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} proof let V be RealLinearSpace; ::_thesis: for A being Subset of V st A is affinely-independent holds for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} let A be Subset of V; ::_thesis: ( A is affinely-independent implies for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} ) assume A1: A is affinely-independent ; ::_thesis: for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} let L be Linear_Combination of A; ::_thesis: ( Sum L = 0. V & sum L = 0 implies Carrier L = {} ) assume that A2: Sum L = 0. V and A3: sum L = 0 ; ::_thesis: Carrier L = {} percases ( A is empty or not A is empty ) ; suppose A is empty ; ::_thesis: Carrier L = {} then Carrier L c= {} by RLVECT_2:def_6; hence Carrier L = {} ; ::_thesis: verum end; suppose not A is empty ; ::_thesis: Carrier L = {} then consider p being VECTOR of V such that A4: p in A and A5: ((- p) + A) \ {(0. V)} is linearly-independent by A1, Def4; A6: A \/ {p} = A by A4, ZFMISC_1:40; consider Lp being Linear_Combination of {p} such that A7: Lp . p = L . p by RLVECT_4:37; set LLp = L - Lp; ((- p) + (L - Lp)) . (0. V) = (L - Lp) . ((0. V) - (- p)) by Def1 .= (L - Lp) . (- (- p)) by RLVECT_1:14 .= (L - Lp) . p by RLVECT_1:17 .= (L . p) - (Lp . p) by RLVECT_2:54 .= 0 by A7 ; then A8: not 0. V in Carrier ((- p) + (L - Lp)) by RLVECT_2:19; A9: Carrier Lp c= {p} by RLVECT_2:def_6; then A10: ( Carrier Lp = {p} or Carrier Lp = {} ) by ZFMISC_1:33; Carrier L c= A by RLVECT_2:def_6; then ( Carrier (L - Lp) c= (Carrier L) \/ (Carrier Lp) & (Carrier L) \/ (Carrier Lp) c= A \/ {p} ) by A9, RLVECT_2:55, XBOOLE_1:13; then A11: Carrier (L - Lp) c= A by A6, XBOOLE_1:1; Carrier ((- p) + (L - Lp)) = (- p) + (Carrier (L - Lp)) by Th16; then Carrier ((- p) + (L - Lp)) c= (- p) + A by A11, RLTOPSP1:8; then Carrier ((- p) + (L - Lp)) c= ((- p) + A) \ {(0. V)} by A8, ZFMISC_1:34; then A12: (- p) + (L - Lp) is Linear_Combination of ((- p) + A) \ {(0. V)} by RLVECT_2:def_6; A13: (L - Lp) + Lp = L + (Lp - Lp) by RLVECT_2:40 .= L + (ZeroLC V) by RLVECT_2:57 .= L by RLVECT_2:41 ; A14: Sum ((- p) + Lp) = ((sum Lp) * (- p)) + (Sum Lp) by Th39 .= ((sum Lp) * (- p)) + ((Lp . p) * p) by RLVECT_2:32 .= ((Lp . p) * (- p)) + ((Lp . p) * p) by A9, Th32 .= (Lp . p) * ((- p) + p) by RLVECT_1:def_5 .= (Lp . p) * (0. V) by RLVECT_1:5 .= 0. V by RLVECT_1:10 ; Sum ((- p) + L) = ((sum L) * (- p)) + (Sum L) by Th39 .= (0. V) + (0. V) by A2, A3, RLVECT_1:10 .= 0. V by RLVECT_1:4 ; then 0. V = Sum (((- p) + (L - Lp)) + ((- p) + Lp)) by A13, Th17 .= (Sum ((- p) + (L - Lp))) + (0. V) by A14, RLVECT_3:1 .= Sum ((- p) + (L - Lp)) by RLVECT_1:4 ; then {} = Carrier ((- p) + (L - Lp)) by A5, A12, RLVECT_3:def_1; then A15: ZeroLC V = (- p) + (L - Lp) by RLVECT_2:def_5; A16: L - Lp = (0. V) + (L - Lp) by Th21 .= (p + (- p)) + (L - Lp) by RLVECT_1:5 .= p + ((- p) + (L - Lp)) by Th19 .= ZeroLC V by A15, Th20 ; then sum (L - Lp) = 0 by Th31; then 0 = 0 + (sum Lp) by A3, A13, Th34 .= 0 + (Lp . p) by A9, Th32 ; then not p in Carrier Lp by RLVECT_2:19; then (Carrier (L - Lp)) \/ (Carrier Lp) = {} by A10, A16, RLVECT_2:def_5, TARSKI:def_1; then Carrier L c= {} by A13, RLVECT_2:37; hence Carrier L = {} ; ::_thesis: verum end; end; end; Lm6: for V being RealLinearSpace for A being Subset of V st ( for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} ) holds for p being VECTOR of V st p in A holds ((- p) + A) \ {(0. V)} is linearly-independent proof let V be RealLinearSpace; ::_thesis: for A being Subset of V st ( for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} ) holds for p being VECTOR of V st p in A holds ((- p) + A) \ {(0. V)} is linearly-independent let A be Subset of V; ::_thesis: ( ( for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} ) implies for p being VECTOR of V st p in A holds ((- p) + A) \ {(0. V)} is linearly-independent ) assume A1: for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} ; ::_thesis: for p being VECTOR of V st p in A holds ((- p) + A) \ {(0. V)} is linearly-independent let p be Element of V; ::_thesis: ( p in A implies ((- p) + A) \ {(0. V)} is linearly-independent ) assume A2: p in A ; ::_thesis: ((- p) + A) \ {(0. V)} is linearly-independent set pA = (- p) + A; set pA0 = ((- p) + A) \ {(0. V)}; (- p) + p = 0. V by RLVECT_1:5; then 0. V in (- p) + A by A2; then A3: (((- p) + A) \ {(0. V)}) \/ {(0. V)} = (- p) + A by ZFMISC_1:116; let L be Linear_Combination of ((- p) + A) \ {(0. V)}; :: according to RLVECT_3:def_1 ::_thesis: ( not Sum L = 0. V or Carrier L = {} ) assume A4: Sum L = 0. V ; ::_thesis: Carrier L = {} reconsider sL = - (sum L) as Real ; consider Lp being Linear_Combination of {(0. V)} such that A5: Lp . (0. V) = sL by RLVECT_4:37; set LLp = L + Lp; set pLLp = p + (L + Lp); A6: Carrier Lp c= {(0. V)} by RLVECT_2:def_6; A7: p + ((- p) + A) = (p + (- p)) + A by Th5 .= (0. V) + A by RLVECT_1:5 .= A by Th6 ; A8: Carrier (p + (L + Lp)) = p + (Carrier (L + Lp)) by Th16; A9: Carrier L c= ((- p) + A) \ {(0. V)} by RLVECT_2:def_6; then ( Carrier (L + Lp) c= (Carrier L) \/ (Carrier Lp) & (Carrier L) \/ (Carrier Lp) c= (((- p) + A) \ {(0. V)}) \/ {(0. V)} ) by A6, RLVECT_2:37, XBOOLE_1:13; then Carrier (L + Lp) c= (- p) + A by A3, XBOOLE_1:1; then Carrier (p + (L + Lp)) c= A by A7, A8, RLTOPSP1:8; then A10: p + (L + Lp) is Linear_Combination of A by RLVECT_2:def_6; A11: sum (p + (L + Lp)) = sum (L + Lp) by Th37; A12: sum (L + Lp) = (sum L) + (sum Lp) by Th34 .= (sum L) + sL by A5, A6, Th32 .= 0 ; then Sum (p + (L + Lp)) = (0 * p) + (Sum (L + Lp)) by Th39 .= (0. V) + (Sum (L + Lp)) by RLVECT_1:10 .= Sum (L + Lp) by RLVECT_1:4 .= (Sum L) + (Sum Lp) by RLVECT_3:1 .= Sum Lp by A4, RLVECT_1:4 .= (Lp . (0. V)) * (0. V) by RLVECT_2:32 .= 0. V by RLVECT_1:10 ; then Carrier (p + (L + Lp)) = {} by A1, A10, A11, A12; then A13: p + (L + Lp) = ZeroLC V by RLVECT_2:def_5; A14: L + Lp = (0. V) + (L + Lp) by Th21 .= ((- p) + p) + (L + Lp) by RLVECT_1:5 .= (- p) + (ZeroLC V) by A13, Th19 .= ZeroLC V by Th20 ; assume Carrier L <> {} ; ::_thesis: contradiction then consider v being set such that A15: v in Carrier L by XBOOLE_0:def_1; reconsider v = v as Element of V by A15; not v in Carrier Lp by A6, A9, A15, XBOOLE_0:def_5; then Lp . v = 0 ; then (L . v) + 0 = (L + Lp) . v by RLVECT_2:def_10 .= 0 by A14, RLVECT_2:20 ; hence contradiction by A15, RLVECT_2:19; ::_thesis: verum end; theorem Th41: :: RLAFFIN1:41 for V being RealLinearSpace for A being Subset of V holds ( A is affinely-independent iff for v being VECTOR of V st v in A holds ((- v) + A) \ {(0. V)} is linearly-independent ) proof let V be RealLinearSpace; ::_thesis: for A being Subset of V holds ( A is affinely-independent iff for v being VECTOR of V st v in A holds ((- v) + A) \ {(0. V)} is linearly-independent ) let A be Subset of V; ::_thesis: ( A is affinely-independent iff for v being VECTOR of V st v in A holds ((- v) + A) \ {(0. V)} is linearly-independent ) hereby ::_thesis: ( ( for v being VECTOR of V st v in A holds ((- v) + A) \ {(0. V)} is linearly-independent ) implies A is affinely-independent ) assume A is affinely-independent ; ::_thesis: for v being VECTOR of V st v in A holds ((- v) + A) \ {(0. V)} is linearly-independent then for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} by Lm5; hence for v being VECTOR of V st v in A holds ((- v) + A) \ {(0. V)} is linearly-independent by Lm6; ::_thesis: verum end; assume A1: for v being VECTOR of V st v in A holds ((- v) + A) \ {(0. V)} is linearly-independent ; ::_thesis: A is affinely-independent assume not A is empty ; :: according to RLAFFIN1:def_4 ::_thesis: ex v being VECTOR of V st ( v in A & ((- v) + A) \ {(0. V)} is linearly-independent ) then consider v being set such that A2: v in A by XBOOLE_0:def_1; reconsider v = v as Element of V by A2; take v ; ::_thesis: ( v in A & ((- v) + A) \ {(0. V)} is linearly-independent ) thus ( v in A & ((- v) + A) \ {(0. V)} is linearly-independent ) by A1, A2; ::_thesis: verum end; theorem Th42: :: RLAFFIN1:42 for V being RealLinearSpace for A being Subset of V holds ( A is affinely-independent iff for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} ) proof let V be RealLinearSpace; ::_thesis: for A being Subset of V holds ( A is affinely-independent iff for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} ) let A be Subset of V; ::_thesis: ( A is affinely-independent iff for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} ) thus ( A is affinely-independent implies for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} ) by Lm5; ::_thesis: ( ( for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} ) implies A is affinely-independent ) assume for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} ; ::_thesis: A is affinely-independent then for p being VECTOR of V st p in A holds ((- p) + A) \ {(0. V)} is linearly-independent by Lm6; hence A is affinely-independent by Th41; ::_thesis: verum end; theorem Th43: :: RLAFFIN1:43 for V being RealLinearSpace for A, B being Subset of V st A is affinely-independent & B c= A holds B is affinely-independent proof let V be RealLinearSpace; ::_thesis: for A, B being Subset of V st A is affinely-independent & B c= A holds B is affinely-independent let A, B be Subset of V; ::_thesis: ( A is affinely-independent & B c= A implies B is affinely-independent ) assume that A1: A is affinely-independent and A2: B c= A ; ::_thesis: B is affinely-independent now__::_thesis:_for_L_being_Linear_Combination_of_B_st_Sum_L_=_0._V_&_sum_L_=_0_holds_ Carrier_L_=_{} let L be Linear_Combination of B; ::_thesis: ( Sum L = 0. V & sum L = 0 implies Carrier L = {} ) assume A3: ( Sum L = 0. V & sum L = 0 ) ; ::_thesis: Carrier L = {} L is Linear_Combination of A by A2, RLVECT_2:21; hence Carrier L = {} by A1, A3, Th42; ::_thesis: verum end; hence B is affinely-independent by Th42; ::_thesis: verum end; registration let V be RealLinearSpace; cluster linearly-independent -> affinely-independent for Element of K19( the carrier of V); coherence for b1 being Subset of V st b1 is linearly-independent holds b1 is affinely-independent proof let A be Subset of V; ::_thesis: ( A is linearly-independent implies A is affinely-independent ) assume A is linearly-independent ; ::_thesis: A is affinely-independent then for L being Linear_Combination of A st Sum L = 0. V & sum L = 0 holds Carrier L = {} by RLVECT_3:def_1; hence A is affinely-independent by Th42; ::_thesis: verum end; end; registration let V be RealLinearSpace; let I be affinely-independent Subset of V; let v be VECTOR of V; clusterv + I -> affinely-independent ; coherence v + I is affinely-independent proof set vI = v + I; now__::_thesis:_for_L_being_Linear_Combination_of_v_+_I_st_Sum_L_=_0._V_&_sum_L_=_0_holds_ Carrier_L_=_{} let L be Linear_Combination of v + I; ::_thesis: ( Sum L = 0. V & sum L = 0 implies Carrier L = {} ) assume that A1: Sum L = 0. V and A2: sum L = 0 ; ::_thesis: Carrier L = {} set vL = (- v) + L; A3: sum ((- v) + L) = 0 by A2, Th37; A4: ( Carrier ((- v) + L) = (- v) + (Carrier L) & Carrier L c= v + I ) by Th16, RLVECT_2:def_6; (- v) + (v + I) = ((- v) + v) + I by Th5 .= (0. V) + I by RLVECT_1:5 .= I by Th6 ; then Carrier ((- v) + L) c= I by A4, RLTOPSP1:8; then A5: (- v) + L is Linear_Combination of I by RLVECT_2:def_6; Sum ((- v) + L) = (0 * (- v)) + (0. V) by A1, A2, Th39 .= (0. V) + (0. V) by RLVECT_1:10 .= 0. V by RLVECT_1:4 ; then Carrier ((- v) + L) = {} by A3, A5, Th42; then A6: (- v) + L = ZeroLC V by RLVECT_2:def_5; L = (0. V) + L by Th21 .= (v + (- v)) + L by RLVECT_1:5 .= v + (ZeroLC V) by A6, Th19 .= ZeroLC V by Th20 ; hence Carrier L = {} by RLVECT_2:def_5; ::_thesis: verum end; hence v + I is affinely-independent by Th42; ::_thesis: verum end; end; theorem :: RLAFFIN1:44 for V being RealLinearSpace for v being VECTOR of V for A being Subset of V st v + A is affinely-independent holds A is affinely-independent proof let V be RealLinearSpace; ::_thesis: for v being VECTOR of V for A being Subset of V st v + A is affinely-independent holds A is affinely-independent let v be VECTOR of V; ::_thesis: for A being Subset of V st v + A is affinely-independent holds A is affinely-independent let A be Subset of V; ::_thesis: ( v + A is affinely-independent implies A is affinely-independent ) assume A1: v + A is affinely-independent ; ::_thesis: A is affinely-independent (- v) + (v + A) = ((- v) + v) + A by Th5 .= (0. V) + A by RLVECT_1:5 .= A by Th6 ; hence A is affinely-independent by A1; ::_thesis: verum end; registration let V be RealLinearSpace; let I be affinely-independent Subset of V; let r be Real; clusterr * I -> affinely-independent ; coherence r * I is affinely-independent proof percases ( r = 0 or r <> 0 ) ; suppose r = 0 ; ::_thesis: r * I is affinely-independent then r * I c= {(0. V)} by Th12; then ( r * I = {} V or r * I = {(0. V)} ) by ZFMISC_1:33; hence r * I is affinely-independent ; ::_thesis: verum end; supposeA1: r <> 0 ; ::_thesis: r * I is affinely-independent now__::_thesis:_for_L_being_Linear_Combination_of_r_*_I_st_Sum_L_=_0._V_&_sum_L_=_0_holds_ Carrier_L_=_{} let L be Linear_Combination of r * I; ::_thesis: ( Sum L = 0. V & sum L = 0 implies Carrier L = {} ) assume that A2: Sum L = 0. V and A3: sum L = 0 ; ::_thesis: Carrier L = {} set rL = (r ") (*) L; A4: Sum ((r ") (*) L) = (r ") * (0. V) by A2, Th40 .= 0. V by RLVECT_1:10 ; A5: ( Carrier ((r ") (*) L) = (r ") * (Carrier L) & Carrier L c= r * I ) by A1, Th23, RLVECT_2:def_6; (r ") * (r * I) = ((r ") * r) * I by Th10 .= 1 * I by A1, XCMPLX_0:def_7 .= I by Th11 ; then Carrier ((r ") (*) L) c= I by A5, Th9; then A6: (r ") (*) L is Linear_Combination of I by RLVECT_2:def_6; sum ((r ") (*) L) = 0 by A1, A3, Th38; then Carrier ((r ") (*) L) = {} by A4, A6, Th42; then A7: (r ") (*) L = ZeroLC V by RLVECT_2:def_5; L = 1 (*) L by Th28 .= (r * (r ")) (*) L by A1, XCMPLX_0:def_7 .= r (*) (ZeroLC V) by A7, Th27 .= ZeroLC V by Th26 ; hence Carrier L = {} by RLVECT_2:def_5; ::_thesis: verum end; hence r * I is affinely-independent by Th42; ::_thesis: verum end; end; end; end; theorem :: RLAFFIN1:45 for r being Real for V being RealLinearSpace for A being Subset of V st r * A is affinely-independent & r <> 0 holds A is affinely-independent proof let r be Real; ::_thesis: for V being RealLinearSpace for A being Subset of V st r * A is affinely-independent & r <> 0 holds A is affinely-independent let V be RealLinearSpace; ::_thesis: for A being Subset of V st r * A is affinely-independent & r <> 0 holds A is affinely-independent let A be Subset of V; ::_thesis: ( r * A is affinely-independent & r <> 0 implies A is affinely-independent ) assume that A1: r * A is affinely-independent and A2: r <> 0 ; ::_thesis: A is affinely-independent (r ") * (r * A) = ((r ") * r) * A by Th10 .= 1 * A by A2, XCMPLX_0:def_7 .= A by Th11 ; hence A is affinely-independent by A1; ::_thesis: verum end; theorem Th46: :: RLAFFIN1:46 for V being RealLinearSpace for A being Subset of V st 0. V in A holds ( A is affinely-independent iff A \ {(0. V)} is linearly-independent ) proof let V be RealLinearSpace; ::_thesis: for A being Subset of V st 0. V in A holds ( A is affinely-independent iff A \ {(0. V)} is linearly-independent ) let A be Subset of V; ::_thesis: ( 0. V in A implies ( A is affinely-independent iff A \ {(0. V)} is linearly-independent ) ) assume A1: 0. V in A ; ::_thesis: ( A is affinely-independent iff A \ {(0. V)} is linearly-independent ) A2: (- (0. V)) + A = (0. V) + A by RLVECT_1:12 .= A by Th6 ; hence ( A is affinely-independent implies A \ {(0. V)} is linearly-independent ) by A1, Th41; ::_thesis: ( A \ {(0. V)} is linearly-independent implies A is affinely-independent ) assume A \ {(0. V)} is linearly-independent ; ::_thesis: A is affinely-independent hence A is affinely-independent by A1, A2, Def4; ::_thesis: verum end; definition let V be RealLinearSpace; let F be Subset-Family of V; attrF is affinely-independent means :Def5: :: RLAFFIN1:def 5 for A being Subset of V st A in F holds A is affinely-independent ; end; :: deftheorem Def5 defines affinely-independent RLAFFIN1:def_5_:_ for V being RealLinearSpace for F being Subset-Family of V holds ( F is affinely-independent iff for A being Subset of V st A in F holds A is affinely-independent ); registration let V be RealLinearSpace; cluster empty -> affinely-independent for Element of K19(K19( the carrier of V)); coherence for b1 being Subset-Family of V st b1 is empty holds b1 is affinely-independent proof let F be Subset-Family of V; ::_thesis: ( F is empty implies F is affinely-independent ) assume A1: F is empty ; ::_thesis: F is affinely-independent let A be Subset of V; :: according to RLAFFIN1:def_5 ::_thesis: ( A in F implies A is affinely-independent ) assume A in F ; ::_thesis: A is affinely-independent hence A is affinely-independent by A1; ::_thesis: verum end; let I be affinely-independent Subset of V; cluster{I} -> affinely-independent for Subset-Family of V; coherence for b1 being Subset-Family of V st b1 = {I} holds b1 is affinely-independent proof for A being Subset of V st A in {I} holds A is affinely-independent by TARSKI:def_1; hence for b1 being Subset-Family of V st b1 = {I} holds b1 is affinely-independent by Def5; ::_thesis: verum end; end; registration let V be RealLinearSpace; cluster empty affinely-independent for Element of K19(K19( the carrier of V)); existence ex b1 being Subset-Family of V st ( b1 is empty & b1 is affinely-independent ) proof take {} (bool the carrier of V) ; ::_thesis: ( {} (bool the carrier of V) is empty & {} (bool the carrier of V) is affinely-independent ) thus ( {} (bool the carrier of V) is empty & {} (bool the carrier of V) is affinely-independent ) ; ::_thesis: verum end; cluster non empty affinely-independent for Element of K19(K19( the carrier of V)); existence ex b1 being Subset-Family of V st ( not b1 is empty & b1 is affinely-independent ) proof take { the affinely-independent Subset of V} ; ::_thesis: ( not { the affinely-independent Subset of V} is empty & { the affinely-independent Subset of V} is affinely-independent ) thus ( not { the affinely-independent Subset of V} is empty & { the affinely-independent Subset of V} is affinely-independent ) ; ::_thesis: verum end; end; theorem :: RLAFFIN1:47 for V being RealLinearSpace for F1, F2 being Subset-Family of V st F1 is affinely-independent & F2 is affinely-independent holds F1 \/ F2 is affinely-independent proof let V be RealLinearSpace; ::_thesis: for F1, F2 being Subset-Family of V st F1 is affinely-independent & F2 is affinely-independent holds F1 \/ F2 is affinely-independent let F1, F2 be Subset-Family of V; ::_thesis: ( F1 is affinely-independent & F2 is affinely-independent implies F1 \/ F2 is affinely-independent ) assume A1: ( F1 is affinely-independent & F2 is affinely-independent ) ; ::_thesis: F1 \/ F2 is affinely-independent let A be Subset of V; :: according to RLAFFIN1:def_5 ::_thesis: ( A in F1 \/ F2 implies A is affinely-independent ) assume A in F1 \/ F2 ; ::_thesis: A is affinely-independent then ( A in F1 or A in F2 ) by XBOOLE_0:def_3; hence A is affinely-independent by A1, Def5; ::_thesis: verum end; theorem :: RLAFFIN1:48 for V being RealLinearSpace for F1, F2 being Subset-Family of V st F1 c= F2 & F2 is affinely-independent holds F1 is affinely-independent proof let V be RealLinearSpace; ::_thesis: for F1, F2 being Subset-Family of V st F1 c= F2 & F2 is affinely-independent holds F1 is affinely-independent let F1, F2 be Subset-Family of V; ::_thesis: ( F1 c= F2 & F2 is affinely-independent implies F1 is affinely-independent ) assume A1: ( F1 c= F2 & F2 is affinely-independent ) ; ::_thesis: F1 is affinely-independent let A be Subset of V; :: according to RLAFFIN1:def_5 ::_thesis: ( A in F1 implies A is affinely-independent ) assume A in F1 ; ::_thesis: A is affinely-independent hence A is affinely-independent by A1, Def5; ::_thesis: verum end; begin definition let RLS be non empty RLSStruct ; let A be Subset of RLS; func Affin A -> Subset of RLS equals :: RLAFFIN1:def 6 meet { B where B is Affine Subset of RLS : A c= B } ; coherence meet { B where B is Affine Subset of RLS : A c= B } is Subset of RLS proof set BB = { B where B is Affine Subset of RLS : A c= B } ; { B where B is Affine Subset of RLS : A c= B } c= bool ([#] RLS) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in { B where B is Affine Subset of RLS : A c= B } or x in bool ([#] RLS) ) assume x in { B where B is Affine Subset of RLS : A c= B } ; ::_thesis: x in bool ([#] RLS) then ex B being Affine Subset of RLS st ( x = B & A c= B ) ; hence x in bool ([#] RLS) ; ::_thesis: verum end; then reconsider BB = { B where B is Affine Subset of RLS : A c= B } as Subset-Family of RLS ; meet BB is Subset of RLS ; hence meet { B where B is Affine Subset of RLS : A c= B } is Subset of RLS ; ::_thesis: verum end; end; :: deftheorem defines Affin RLAFFIN1:def_6_:_ for RLS being non empty RLSStruct for A being Subset of RLS holds Affin A = meet { B where B is Affine Subset of RLS : A c= B } ; registration let RLS be non empty RLSStruct ; let A be Subset of RLS; cluster Affin A -> Affine ; coherence Affin A is Affine proof set BB = { B where B is Affine Subset of RLS : A c= B } ; let v1, v2 be Element of RLS; :: according to RUSUB_4:def_4 ::_thesis: for b1 being Element of REAL holds ( not v1 in Affin A or not v2 in Affin A or ((1 - b1) * v1) + (b1 * v2) in Affin A ) let r be Real; ::_thesis: ( not v1 in Affin A or not v2 in Affin A or ((1 - r) * v1) + (r * v2) in Affin A ) assume that A1: v1 in Affin A and A2: v2 in Affin A ; ::_thesis: ((1 - r) * v1) + (r * v2) in Affin A A3: now__::_thesis:_for_Y_being_set_st_Y_in__{__B_where_B_is_Affine_Subset_of_RLS_:_A_c=_B__}__holds_ ((1_-_r)_*_v1)_+_(r_*_v2)_in_Y let Y be set ; ::_thesis: ( Y in { B where B is Affine Subset of RLS : A c= B } implies ((1 - r) * v1) + (r * v2) in Y ) assume A4: Y in { B where B is Affine Subset of RLS : A c= B } ; ::_thesis: ((1 - r) * v1) + (r * v2) in Y then consider B being Affine Subset of RLS such that A5: Y = B and A c= B ; ( v1 in B & v2 in B ) by A1, A2, A4, A5, SETFAM_1:def_1; hence ((1 - r) * v1) + (r * v2) in Y by A5, RUSUB_4:def_4; ::_thesis: verum end; { B where B is Affine Subset of RLS : A c= B } <> {} by A1, SETFAM_1:def_1; hence ((1 - r) * v1) + (r * v2) in Affin A by A3, SETFAM_1:def_1; ::_thesis: verum end; end; Lm7: for V being non empty RLSStruct for A being Subset of V holds A c= Affin A proof let V be non empty RLSStruct ; ::_thesis: for A being Subset of V holds A c= Affin A let A be Subset of V; ::_thesis: A c= Affin A set BB = { B where B is Affine Subset of V : A c= B } ; A1: now__::_thesis:_for_Y_being_set_st_Y_in__{__B_where_B_is_Affine_Subset_of_V_:_A_c=_B__}__holds_ A_c=_Y let Y be set ; ::_thesis: ( Y in { B where B is Affine Subset of V : A c= B } implies A c= Y ) assume Y in { B where B is Affine Subset of V : A c= B } ; ::_thesis: A c= Y then ex B being Affine Subset of V st ( Y = B & A c= B ) ; hence A c= Y ; ::_thesis: verum end; [#] V is Affine by RUSUB_4:22; then [#] V in { B where B is Affine Subset of V : A c= B } ; hence A c= Affin A by A1, SETFAM_1:5; ::_thesis: verum end; Lm8: for V being non empty RLSStruct for A being Affine Subset of V holds A = Affin A proof let V be non empty RLSStruct ; ::_thesis: for A being Affine Subset of V holds A = Affin A let A be Affine Subset of V; ::_thesis: A = Affin A set BB = { B where B is Affine Subset of V : A c= B } ; A in { B where B is Affine Subset of V : A c= B } ; then A1: Affin A c= A by SETFAM_1:3; A c= Affin A by Lm7; hence A = Affin A by A1, XBOOLE_0:def_10; ::_thesis: verum end; registration let RLS be non empty RLSStruct ; let A be empty Subset of RLS; cluster Affin A -> empty ; coherence Affin A is empty proof {} RLS is Affine by RUSUB_4:22; hence Affin A is empty by Lm8; ::_thesis: verum end; end; registration let RLS be non empty RLSStruct ; let A be non empty Subset of RLS; cluster Affin A -> non empty ; coherence not Affin A is empty proof A c= Affin A by Lm7; hence not Affin A is empty ; ::_thesis: verum end; end; theorem :: RLAFFIN1:49 for RLS being non empty RLSStruct for A being Subset of RLS holds A c= Affin A by Lm7; theorem :: RLAFFIN1:50 for RLS being non empty RLSStruct for A being Affine Subset of RLS holds A = Affin A by Lm8; theorem Th51: :: RLAFFIN1:51 for RLS being non empty RLSStruct for A, B being Subset of RLS st A c= B & B is Affine holds Affin A c= B proof let RLS be non empty RLSStruct ; ::_thesis: for A, B being Subset of RLS st A c= B & B is Affine holds Affin A c= B let A, B be Subset of RLS; ::_thesis: ( A c= B & B is Affine implies Affin A c= B ) assume ( A c= B & B is Affine ) ; ::_thesis: Affin A c= B then B in { C where C is Affine Subset of RLS : A c= C } ; hence Affin A c= B by SETFAM_1:3; ::_thesis: verum end; theorem Th52: :: RLAFFIN1:52 for RLS being non empty RLSStruct for A, B being Subset of RLS st A c= B holds Affin A c= Affin B proof let RLS be non empty RLSStruct ; ::_thesis: for A, B being Subset of RLS st A c= B holds Affin A c= Affin B let A, B be Subset of RLS; ::_thesis: ( A c= B implies Affin A c= Affin B ) assume A1: A c= B ; ::_thesis: Affin A c= Affin B B c= Affin B by Lm7; then A c= Affin B by A1, XBOOLE_1:1; hence Affin A c= Affin B by Th51; ::_thesis: verum end; theorem Th53: :: RLAFFIN1:53 for V being RealLinearSpace for v being VECTOR of V for A being Subset of V holds Affin (v + A) = v + (Affin A) proof let V be RealLinearSpace; ::_thesis: for v being VECTOR of V for A being Subset of V holds Affin (v + A) = v + (Affin A) let v be VECTOR of V; ::_thesis: for A being Subset of V holds Affin (v + A) = v + (Affin A) let A be Subset of V; ::_thesis: Affin (v + A) = v + (Affin A) v + A c= v + (Affin A) by Lm7, RLTOPSP1:8; then A1: Affin (v + A) c= v + (Affin A) by Th51, RUSUB_4:31; (- v) + (v + A) = ((- v) + v) + A by Th5 .= (0. V) + A by RLVECT_1:5 .= A by Th6 ; then A c= (- v) + (Affin (v + A)) by Lm7, RLTOPSP1:8; then A2: Affin A c= (- v) + (Affin (v + A)) by Th51, RUSUB_4:31; v + ((- v) + (Affin (v + A))) = (v + (- v)) + (Affin (v + A)) by Th5 .= (0. V) + (Affin (v + A)) by RLVECT_1:5 .= Affin (v + A) by Th6 ; then v + (Affin A) c= Affin (v + A) by A2, RLTOPSP1:8; hence Affin (v + A) = v + (Affin A) by A1, XBOOLE_0:def_10; ::_thesis: verum end; theorem Th54: :: RLAFFIN1:54 for r being Real for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for AR being Subset of R st AR is Affine holds r * AR is Affine proof let r be Real; ::_thesis: for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for AR being Subset of R st AR is Affine holds r * AR is Affine let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: for AR being Subset of R st AR is Affine holds r * AR is Affine let AR be Subset of R; ::_thesis: ( AR is Affine implies r * AR is Affine ) assume A1: AR is Affine ; ::_thesis: r * AR is Affine let v1, v2 be VECTOR of R; :: according to RUSUB_4:def_4 ::_thesis: for b1 being Element of REAL holds ( not v1 in r * AR or not v2 in r * AR or ((1 - b1) * v1) + (b1 * v2) in r * AR ) let s be Real; ::_thesis: ( not v1 in r * AR or not v2 in r * AR or ((1 - s) * v1) + (s * v2) in r * AR ) assume v1 in r * AR ; ::_thesis: ( not v2 in r * AR or ((1 - s) * v1) + (s * v2) in r * AR ) then consider w1 being Element of R such that A2: v1 = r * w1 and A3: w1 in AR ; assume v2 in r * AR ; ::_thesis: ((1 - s) * v1) + (s * v2) in r * AR then consider w2 being Element of R such that A4: v2 = r * w2 and A5: w2 in AR ; A6: ((1 - s) * w1) + (s * w2) in AR by A1, A3, A5, RUSUB_4:def_4; A7: (1 - s) * (r * w1) = ((1 - s) * r) * w1 by RLVECT_1:def_7 .= r * ((1 - s) * w1) by RLVECT_1:def_7 ; s * (r * w2) = (s * r) * w2 by RLVECT_1:def_7 .= r * (s * w2) by RLVECT_1:def_7 ; then ((1 - s) * v1) + (s * v2) = r * (((1 - s) * w1) + (s * w2)) by A2, A4, A7, RLVECT_1:def_5; hence ((1 - s) * v1) + (s * v2) in r * AR by A6; ::_thesis: verum end; theorem Th55: :: RLAFFIN1:55 for r being Real for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for AR being Subset of R st r <> 0 holds Affin (r * AR) = r * (Affin AR) proof let r be Real; ::_thesis: for R being non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct for AR being Subset of R st r <> 0 holds Affin (r * AR) = r * (Affin AR) let R be non empty vector-distributive scalar-distributive scalar-associative scalar-unital RLSStruct ; ::_thesis: for AR being Subset of R st r <> 0 holds Affin (r * AR) = r * (Affin AR) let AR be Subset of R; ::_thesis: ( r <> 0 implies Affin (r * AR) = r * (Affin AR) ) assume A1: r <> 0 ; ::_thesis: Affin (r * AR) = r * (Affin AR) (r ") * (r * AR) = ((r ") * r) * AR by Th10 .= 1 * AR by A1, XCMPLX_0:def_7 .= AR by Th11 ; then AR c= (r ") * (Affin (r * AR)) by Lm7, Th9; then A2: Affin AR c= (r ") * (Affin (r * AR)) by Th51, Th54; r * AR c= r * (Affin AR) by Lm7, Th9; then A3: Affin (r * AR) c= r * (Affin AR) by Th51, Th54; r * ((r ") * (Affin (r * AR))) = (r * (r ")) * (Affin (r * AR)) by Th10 .= 1 * (Affin (r * AR)) by A1, XCMPLX_0:def_7 .= Affin (r * AR) by Th11 ; then r * (Affin AR) c= Affin (r * AR) by A2, Th9; hence Affin (r * AR) = r * (Affin AR) by A3, XBOOLE_0:def_10; ::_thesis: verum end; theorem :: RLAFFIN1:56 for r being Real for V being RealLinearSpace for A being Subset of V holds Affin (r * A) = r * (Affin A) proof let r be Real; ::_thesis: for V being RealLinearSpace for A being Subset of V holds Affin (r * A) = r * (Affin A) let V be RealLinearSpace; ::_thesis: for A being Subset of V holds Affin (r * A) = r * (Affin A) let A be Subset of V; ::_thesis: Affin (r * A) = r * (Affin A) percases ( r = 0 or r <> 0 ) ; supposeA1: r = 0 ; ::_thesis: Affin (r * A) = r * (Affin A) then A2: r * (Affin A) c= {(0. V)} by Th12; A3: r * (Affin A) c= r * A proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in r * (Affin A) or x in r * A ) assume A4: x in r * (Affin A) ; ::_thesis: x in r * A then ex v being Element of V st ( x = r * v & v in Affin A ) ; then not A is empty ; then consider v being set such that A5: v in A by XBOOLE_0:def_1; reconsider v = v as Element of V by A5; A6: r * v in r * A by A5; x = 0. V by A2, A4, TARSKI:def_1; hence x in r * A by A1, A6, RLVECT_1:10; ::_thesis: verum end; r * A c= {(0. V)} by A1, Th12; then A7: ( r * A is empty or r * A = {(0. V)} ) by ZFMISC_1:33; {(0. V)} is Affine by RUSUB_4:23; then A8: Affin (r * A) = r * A by A7, Lm8; r * A c= r * (Affin A) by Lm7, Th9; hence Affin (r * A) = r * (Affin A) by A3, A8, XBOOLE_0:def_10; ::_thesis: verum end; suppose r <> 0 ; ::_thesis: Affin (r * A) = r * (Affin A) hence Affin (r * A) = r * (Affin A) by Th55; ::_thesis: verum end; end; end; theorem Th57: :: RLAFFIN1:57 for V being RealLinearSpace for v being VECTOR of V for A being Subset of V st v in Affin A holds Affin A = v + (Up (Lin ((- v) + A))) proof let V be RealLinearSpace; ::_thesis: for v being VECTOR of V for A being Subset of V st v in Affin A holds Affin A = v + (Up (Lin ((- v) + A))) let v be VECTOR of V; ::_thesis: for A being Subset of V st v in Affin A holds Affin A = v + (Up (Lin ((- v) + A))) let A be Subset of V; ::_thesis: ( v in Affin A implies Affin A = v + (Up (Lin ((- v) + A))) ) set vA = (- v) + A; set BB = { B where B is Affine Subset of V : (- v) + A c= B } ; A1: (- v) + A c= Up (Lin ((- v) + A)) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in (- v) + A or x in Up (Lin ((- v) + A)) ) assume x in (- v) + A ; ::_thesis: x in Up (Lin ((- v) + A)) then x in Lin ((- v) + A) by RLVECT_3:15; hence x in Up (Lin ((- v) + A)) by STRUCT_0:def_5; ::_thesis: verum end; Up (Lin ((- v) + A)) is Affine by RUSUB_4:24; then A2: Up (Lin ((- v) + A)) in { B where B is Affine Subset of V : (- v) + A c= B } by A1; then A3: Affin ((- v) + A) c= Up (Lin ((- v) + A)) by SETFAM_1:3; assume v in Affin A ; ::_thesis: Affin A = v + (Up (Lin ((- v) + A))) then (- v) + v in (- v) + (Affin A) ; then A4: 0. V in (- v) + (Affin A) by RLVECT_1:5; now__::_thesis:_for_Y_being_set_st_Y_in__{__B_where_B_is_Affine_Subset_of_V_:_(-_v)_+_A_c=_B__}__holds_ Up_(Lin_((-_v)_+_A))_c=_Y let Y be set ; ::_thesis: ( Y in { B where B is Affine Subset of V : (- v) + A c= B } implies Up (Lin ((- v) + A)) c= Y ) A5: Affin ((- v) + A) = (- v) + (Affin A) by Th53; assume Y in { B where B is Affine Subset of V : (- v) + A c= B } ; ::_thesis: Up (Lin ((- v) + A)) c= Y then consider B being Affine Subset of V such that A6: Y = B and A7: (- v) + A c= B ; A8: Lin ((- v) + A) is Subspace of Lin B by A7, RLVECT_3:20; Affin ((- v) + A) c= B by A7, Th51; then B = the carrier of (Lin B) by A4, A5, RUSUB_4:26; hence Up (Lin ((- v) + A)) c= Y by A6, A8, RLSUB_1:def_2; ::_thesis: verum end; then Up (Lin ((- v) + A)) c= Affin ((- v) + A) by A2, SETFAM_1:5; then Up (Lin ((- v) + A)) = Affin ((- v) + A) by A3, XBOOLE_0:def_10; hence v + (Up (Lin ((- v) + A))) = v + ((- v) + (Affin A)) by Th53 .= (v + (- v)) + (Affin A) by Th5 .= (0. V) + (Affin A) by RLVECT_1:5 .= Affin A by Th6 ; ::_thesis: verum end; Lm9: for V being RealLinearSpace for A being Subset of V holds Lin (A \/ {(0. V)}) = Lin A proof let V be RealLinearSpace; ::_thesis: for A being Subset of V holds Lin (A \/ {(0. V)}) = Lin A let A be Subset of V; ::_thesis: Lin (A \/ {(0. V)}) = Lin A {(0. V)} = the carrier of ((0). V) by RLSUB_1:def_3; then Lin {(0. V)} = (0). V by RLVECT_3:18; hence Lin (A \/ {(0. V)}) = (Lin A) + ((0). V) by RLVECT_3:22 .= Lin A by RLSUB_2:9 ; ::_thesis: verum end; theorem Th58: :: RLAFFIN1:58 for V being RealLinearSpace for A being Subset of V holds ( A is affinely-independent iff for B being Subset of V st B c= A & Affin A = Affin B holds A = B ) proof let V be RealLinearSpace; ::_thesis: for A being Subset of V holds ( A is affinely-independent iff for B being Subset of V st B c= A & Affin A = Affin B holds A = B ) let A be Subset of V; ::_thesis: ( A is affinely-independent iff for B being Subset of V st B c= A & Affin A = Affin B holds A = B ) hereby ::_thesis: ( ( for B being Subset of V st B c= A & Affin A = Affin B holds A = B ) implies A is affinely-independent ) assume A1: A is affinely-independent ; ::_thesis: for B being Subset of V st B c= A & Affin A = Affin B holds not A <> B let B be Subset of V; ::_thesis: ( B c= A & Affin A = Affin B implies not A <> B ) assume that A2: B c= A and A3: Affin A = Affin B ; ::_thesis: not A <> B assume A <> B ; ::_thesis: contradiction then B c< A by A2, XBOOLE_0:def_8; then consider p being set such that A4: p in A and A5: not p in B by XBOOLE_0:6; reconsider p = p as Element of V by A4; A6: A \ {p} c= Affin (A \ {p}) by Lm7; not B is empty by A3, A4; then consider q being set such that A7: q in B by XBOOLE_0:def_1; reconsider q = q as Element of V by A7; - (- q) = q by RLVECT_1:17; then A8: (- q) + p <> 0. V by A5, A7, RLVECT_1:def_10; set qA0 = ((- q) + A) \ {(0. V)}; (- q) + p in (- q) + A by A4; then A9: (- q) + p in ((- q) + A) \ {(0. V)} by A8, ZFMISC_1:56; ((- q) + A) \ {(0. V)} is linearly-independent by A1, A2, A7, Th41; then A10: not (- q) + p in Lin ((((- q) + A) \ {(0. V)}) \ {((- q) + p)}) by A9, RLVECT_5:17; A11: q + ((- q) + p) = (q + (- q)) + p by RLVECT_1:def_3 .= (0. V) + p by RLVECT_1:5 .= p by RLVECT_1:4 ; (- q) + q = 0. V by RLVECT_1:5; then 0. V in (- q) + A by A2, A7; then A12: 0. V in ((- q) + A) \ {((- q) + p)} by A8, ZFMISC_1:56; (((- q) + A) \ {(0. V)}) \ {((- q) + p)} = ((- q) + A) \ ({(0. V)} \/ {((- q) + p)}) by XBOOLE_1:41 .= (((- q) + A) \ {((- q) + p)}) \ {(0. V)} by XBOOLE_1:41 ; then A13: Lin ((((- q) + A) \ {(0. V)}) \ {((- q) + p)}) = Lin (((((- q) + A) \ {((- q) + p)}) \ {(0. V)}) \/ {(0. V)}) by Lm9 .= Lin (((- q) + A) \ {((- q) + p)}) by A12, ZFMISC_1:116 .= Lin (((- q) + A) \ ((- q) + {p})) by Lm3 .= Lin ((- q) + (A \ {p})) by Lm2 ; q in A \ {p} by A2, A5, A7, ZFMISC_1:56; then A14: Affin (A \ {p}) = q + (Up (Lin ((((- q) + A) \ {(0. V)}) \ {((- q) + p)}))) by A6, A13, Th57; A15: not p in Affin (A \ {p}) proof assume p in Affin (A \ {p}) ; ::_thesis: contradiction then consider v being Element of V such that A16: p = q + v and A17: v in Up (Lin ((((- q) + A) \ {(0. V)}) \ {((- q) + p)})) by A14; (- q) + p = v by A11, A16, RLVECT_1:8; hence contradiction by A10, A17, STRUCT_0:def_5; ::_thesis: verum end; B c= A \ {p} by A2, A5, ZFMISC_1:34; then A18: Affin B c= Affin (A \ {p}) by Th52; Affin (A \ {p}) c= Affin A by Th52, XBOOLE_1:36; then A19: Affin A = Affin (A \ {p}) by A3, A18, XBOOLE_0:def_10; A c= Affin A by Lm7; hence contradiction by A4, A15, A19; ::_thesis: verum end; assume A20: for B being Subset of V st B c= A & Affin A = Affin B holds A = B ; ::_thesis: A is affinely-independent assume not A is affinely-independent ; ::_thesis: contradiction then consider p being Element of V such that A21: p in A and A22: not ((- p) + A) \ {(0. V)} is linearly-independent by Th41; set L = Lin (((- p) + A) \ {(0. V)}); ((- p) + A) \ {(0. V)} c= the carrier of (Lin (((- p) + A) \ {(0. V)})) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in ((- p) + A) \ {(0. V)} or x in the carrier of (Lin (((- p) + A) \ {(0. V)})) ) assume x in ((- p) + A) \ {(0. V)} ; ::_thesis: x in the carrier of (Lin (((- p) + A) \ {(0. V)})) then x in Lin (((- p) + A) \ {(0. V)}) by RLVECT_3:15; hence x in the carrier of (Lin (((- p) + A) \ {(0. V)})) by STRUCT_0:def_5; ::_thesis: verum end; then reconsider pA0 = ((- p) + A) \ {(0. V)} as Subset of (Lin (((- p) + A) \ {(0. V)})) ; (- p) + p = 0. V by RLVECT_1:5; then A23: 0. V in (- p) + A by A21; then A24: pA0 \/ {(0. V)} = (- p) + A by ZFMISC_1:116; Lin pA0 = Lin (((- p) + A) \ {(0. V)}) by RLVECT_5:20; then consider b being Subset of (Lin (((- p) + A) \ {(0. V)})) such that A25: b c= pA0 and A26: b is linearly-independent and A27: Lin b = Lin (((- p) + A) \ {(0. V)}) by RLVECT_3:25; reconsider B = b as linearly-independent Subset of V by A26, RLVECT_5:14; A28: B \/ {(0. V)} c= pA0 \/ {(0. V)} by A25, XBOOLE_1:9; 0. V in {(0. V)} by TARSKI:def_1; then ( p + (0. V) = p & 0. V in B \/ {(0. V)} ) by RLVECT_1:4, XBOOLE_0:def_3; then A29: p in p + (B \/ {(0. V)}) ; A30: p + (B \/ {(0. V)}) c= Affin (p + (B \/ {(0. V)})) by Lm7; A31: p + ((- p) + A) = (p + (- p)) + A by Th5 .= (0. V) + A by RLVECT_1:5 .= A by Th6 ; A32: (- p) + (p + (B \/ {(0. V)})) = ((- p) + p) + (B \/ {(0. V)}) by Th5 .= (0. V) + (B \/ {(0. V)}) by RLVECT_1:5 .= B \/ {(0. V)} by Th6 ; A c= Affin A by Lm7; then Affin A = p + (Up (Lin ((- p) + A))) by A21, Th57 .= p + (Up (Lin ((((- p) + A) \ {(0. V)}) \/ {(0. V)}))) by A23, ZFMISC_1:116 .= p + (Up (Lin (((- p) + A) \ {(0. V)}))) by Lm9 .= p + (Up (Lin B)) by A27, RLVECT_5:20 .= p + (Up (Lin ((- p) + (p + (B \/ {(0. V)}))))) by A32, Lm9 .= Affin (p + (B \/ {(0. V)})) by A29, A30, Th57 ; then pA0 = (B \/ {(0. V)}) \ {(0. V)} by A20, A24, A28, A31, A32, RLTOPSP1:8 .= B by RLVECT_3:6, ZFMISC_1:117 ; hence contradiction by A22; ::_thesis: verum end; theorem Th59: :: RLAFFIN1:59 for V being RealLinearSpace for A being Subset of V holds Affin A = { (Sum L) where L is Linear_Combination of A : sum L = 1 } proof let V be RealLinearSpace; ::_thesis: for A being Subset of V holds Affin A = { (Sum L) where L is Linear_Combination of A : sum L = 1 } let A be Subset of V; ::_thesis: Affin A = { (Sum L) where L is Linear_Combination of A : sum L = 1 } set S = { (Sum L) where L is Linear_Combination of A : sum L = 1 } ; percases ( A is empty or not A is empty ) ; supposeA1: A is empty ; ::_thesis: Affin A = { (Sum L) where L is Linear_Combination of A : sum L = 1 } assume Affin A <> { (Sum L) where L is Linear_Combination of A : sum L = 1 } ; ::_thesis: contradiction then not { (Sum L) where L is Linear_Combination of A : sum L = 1 } is empty by A1; then consider x being set such that A2: x in { (Sum L) where L is Linear_Combination of A : sum L = 1 } by XBOOLE_0:def_1; consider L being Linear_Combination of A such that x = Sum L and A3: sum L = 1 by A2; A = {} the carrier of V by A1; then L = ZeroLC V by RLVECT_2:23; hence contradiction by A3, Th31; ::_thesis: verum end; suppose not A is empty ; ::_thesis: Affin A = { (Sum L) where L is Linear_Combination of A : sum L = 1 } then consider p being set such that A4: p in A by XBOOLE_0:def_1; reconsider p = p as Element of V by A4; A c= Affin A by Lm7; then A5: Affin A = p + (Up (Lin ((- p) + A))) by A4, Th57; thus Affin A c= { (Sum L) where L is Linear_Combination of A : sum L = 1 } :: according to XBOOLE_0:def_10 ::_thesis: { (Sum L) where L is Linear_Combination of A : sum L = 1 } c= Affin A proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Affin A or x in { (Sum L) where L is Linear_Combination of A : sum L = 1 } ) assume x in Affin A ; ::_thesis: x in { (Sum L) where L is Linear_Combination of A : sum L = 1 } then consider v being VECTOR of V such that A6: x = p + v and A7: v in Up (Lin ((- p) + A)) by A5; v in Lin ((- p) + A) by A7, STRUCT_0:def_5; then consider L being Linear_Combination of (- p) + A such that A8: Sum L = v by RLVECT_3:14; set pL = p + L; consider Lp being Linear_Combination of {(0. V)} such that A9: Lp . (0. V) = 1 - (sum L) by RLVECT_4:37; set pLL = p + (L + Lp); set pLp = p + Lp; A10: Carrier Lp c= {(0. V)} by RLVECT_2:def_6; then A11: p + (Carrier Lp) c= p + {(0. V)} by RLTOPSP1:8; A12: ( Carrier (p + L) = p + (Carrier L) & Carrier L c= (- p) + A ) by Th16, RLVECT_2:def_6; p + ((- p) + A) = (p + (- p)) + A by Th5 .= (0. V) + A by RLVECT_1:5 .= A by Th6 ; then A13: Carrier (p + L) c= A by A12, RLTOPSP1:8; A14: ( Carrier ((p + L) + (p + Lp)) c= (Carrier (p + L)) \/ (Carrier (p + Lp)) & p + (L + Lp) = (p + L) + (p + Lp) ) by Th17, RLVECT_2:37; ( Carrier (p + Lp) = p + (Carrier Lp) & p + {(0. V)} = {(p + (0. V))} ) by Lm3, Th16; then Carrier (p + Lp) c= {p} by A11, RLVECT_1:4; then (Carrier (p + L)) \/ (Carrier (p + Lp)) c= A \/ {p} by A13, XBOOLE_1:13; then Carrier (p + (L + Lp)) c= A \/ {p} by A14, XBOOLE_1:1; then Carrier (p + (L + Lp)) c= A by A4, ZFMISC_1:40; then A15: p + (L + Lp) is Linear_Combination of A by RLVECT_2:def_6; A16: sum (p + (L + Lp)) = sum (L + Lp) by Th37; A17: sum (L + Lp) = (sum L) + (sum Lp) by Th34 .= (sum L) + (1 - (sum L)) by A9, A10, Th32 .= 1 ; then Sum (p + (L + Lp)) = (1 * p) + (Sum (L + Lp)) by Th39 .= (1 * p) + (v + (Sum Lp)) by A8, RLVECT_3:1 .= (1 * p) + (v + ((Lp . (0. V)) * (0. V))) by RLVECT_2:32 .= (1 * p) + (v + (0. V)) by RLVECT_1:10 .= p + (v + (0. V)) by RLVECT_1:def_8 .= x by A6, RLVECT_1:4 ; hence x in { (Sum L) where L is Linear_Combination of A : sum L = 1 } by A15, A16, A17; ::_thesis: verum end; let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in { (Sum L) where L is Linear_Combination of A : sum L = 1 } or x in Affin A ) assume x in { (Sum L) where L is Linear_Combination of A : sum L = 1 } ; ::_thesis: x in Affin A then consider L being Linear_Combination of A such that A18: Sum L = x and A19: sum L = 1 ; set pL = (- p) + L; Carrier L c= A by RLVECT_2:def_6; then A20: (- p) + (Carrier L) c= (- p) + A by RLTOPSP1:8; (- p) + (Carrier L) = Carrier ((- p) + L) by Th16; then (- p) + L is Linear_Combination of (- p) + A by A20, RLVECT_2:def_6; then Sum ((- p) + L) in Lin ((- p) + A) by RLVECT_3:14; then A21: Sum ((- p) + L) in Up (Lin ((- p) + A)) by STRUCT_0:def_5; p + (Sum ((- p) + L)) = p + ((1 * (- p)) + (Sum L)) by A19, Th39 .= p + ((- p) + (Sum L)) by RLVECT_1:def_8 .= (p + (- p)) + (Sum L) by RLVECT_1:def_3 .= (0. V) + (Sum L) by RLVECT_1:5 .= x by A18, RLVECT_1:4 ; hence x in Affin A by A5, A21; ::_thesis: verum end; end; end; theorem Th60: :: RLAFFIN1:60 for V being RealLinearSpace for A being Subset of V for I being affinely-independent Subset of V st I c= A holds ex Ia being affinely-independent Subset of V st ( I c= Ia & Ia c= A & Affin Ia = Affin A ) proof let V be RealLinearSpace; ::_thesis: for A being Subset of V for I being affinely-independent Subset of V st I c= A holds ex Ia being affinely-independent Subset of V st ( I c= Ia & Ia c= A & Affin Ia = Affin A ) let A be Subset of V; ::_thesis: for I being affinely-independent Subset of V st I c= A holds ex Ia being affinely-independent Subset of V st ( I c= Ia & Ia c= A & Affin Ia = Affin A ) let I be affinely-independent Subset of V; ::_thesis: ( I c= A implies ex Ia being affinely-independent Subset of V st ( I c= Ia & Ia c= A & Affin Ia = Affin A ) ) assume A1: I c= A ; ::_thesis: ex Ia being affinely-independent Subset of V st ( I c= Ia & Ia c= A & Affin Ia = Affin A ) A2: A c= Affin A by Lm7; percases ( I is empty or not I is empty ) ; supposeA3: I is empty ; ::_thesis: ex Ia being affinely-independent Subset of V st ( I c= Ia & Ia c= A & Affin Ia = Affin A ) percases ( A is empty or not A is empty ) ; supposeA4: A is empty ; ::_thesis: ex Ia being affinely-independent Subset of V st ( I c= Ia & Ia c= A & Affin Ia = Affin A ) take I ; ::_thesis: ( I c= I & I c= A & Affin I = Affin A ) thus ( I c= I & I c= A & Affin I = Affin A ) by A3, A4; ::_thesis: verum end; suppose not A is empty ; ::_thesis: ex Ia being affinely-independent Subset of V st ( I c= Ia & Ia c= A & Affin Ia = Affin A ) then consider p being set such that A5: p in A by XBOOLE_0:def_1; reconsider p = p as Element of V by A5; set L = Lin ((- p) + A); (- p) + A c= [#] (Lin ((- p) + A)) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in (- p) + A or x in [#] (Lin ((- p) + A)) ) assume x in (- p) + A ; ::_thesis: x in [#] (Lin ((- p) + A)) then x in Lin ((- p) + A) by RLVECT_3:15; hence x in [#] (Lin ((- p) + A)) by STRUCT_0:def_5; ::_thesis: verum end; then reconsider pA = (- p) + A as Subset of (Lin ((- p) + A)) ; Lin ((- p) + A) = Lin pA by RLVECT_5:20; then consider Ia being Subset of (Lin ((- p) + A)) such that A6: Ia c= pA and A7: Ia is linearly-independent and A8: Lin Ia = Lin ((- p) + A) by RLVECT_3:25; [#] (Lin ((- p) + A)) c= [#] V by RLSUB_1:def_2; then reconsider IA = Ia as Subset of V by XBOOLE_1:1; set IA0 = IA \/ {(0. V)}; not 0. V in IA by A7, RLVECT_3:6, RLVECT_5:14; then A9: (IA \/ {(0. V)}) \ {(0. V)} = IA by ZFMISC_1:117; 0. V in {(0. V)} by TARSKI:def_1; then A10: 0. V in IA \/ {(0. V)} by XBOOLE_0:def_3; IA is linearly-independent by A7, RLVECT_5:14; then IA \/ {(0. V)} is affinely-independent by A9, A10, Th46; then reconsider pIA0 = p + (IA \/ {(0. V)}) as affinely-independent Subset of V ; take pIA0 ; ::_thesis: ( I c= pIA0 & pIA0 c= A & Affin pIA0 = Affin A ) thus I c= pIA0 by A3, XBOOLE_1:2; ::_thesis: ( pIA0 c= A & Affin pIA0 = Affin A ) thus pIA0 c= A ::_thesis: Affin pIA0 = Affin A proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in pIA0 or x in A ) assume x in pIA0 ; ::_thesis: x in A then consider v being VECTOR of V such that A11: x = p + v and A12: v in IA \/ {(0. V)} ; percases ( v in IA or v in {(0. V)} ) by A12, XBOOLE_0:def_3; suppose v in IA ; ::_thesis: x in A then v in { ((- p) + w) where w is VECTOR of V : w in A } by A6; then consider w being VECTOR of V such that A13: v = (- p) + w and A14: w in A ; x = (p + (- p)) + w by A11, A13, RLVECT_1:def_3 .= (0. V) + w by RLVECT_1:5 .= w by RLVECT_1:4 ; hence x in A by A14; ::_thesis: verum end; suppose v in {(0. V)} ; ::_thesis: x in A then v = 0. V by TARSKI:def_1; hence x in A by A5, A11, RLVECT_1:4; ::_thesis: verum end; end; end; A15: pIA0 c= Affin pIA0 by Lm7; A16: (- p) + pIA0 = ((- p) + p) + (IA \/ {(0. V)}) by Th5 .= (0. V) + (IA \/ {(0. V)}) by RLVECT_1:5 .= IA \/ {(0. V)} by Th6 ; p + (0. V) = p by RLVECT_1:def_4; then p in pIA0 by A10; hence Affin pIA0 = p + (Up (Lin (IA \/ {(0. V)}))) by A15, A16, Th57 .= p + (Up (Lin IA)) by Lm9 .= p + (Up (Lin ((- p) + A))) by A8, RLVECT_5:20 .= Affin A by A2, A5, Th57 ; ::_thesis: verum end; end; end; suppose not I is empty ; ::_thesis: ex Ia being affinely-independent Subset of V st ( I c= Ia & Ia c= A & Affin Ia = Affin A ) then consider p being set such that A17: p in I by XBOOLE_0:def_1; reconsider p = p as Element of V by A17; A18: ((- p) + I) \ {(0. V)} is linearly-independent by A17, Th41; A19: (- p) + I c= (- p) + A by A1, RLTOPSP1:8; set L = Lin ((- p) + A); A20: ((- p) + I) \ {(0. V)} c= (- p) + I by XBOOLE_1:36; A21: (- p) + A c= Up (Lin ((- p) + A)) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in (- p) + A or x in Up (Lin ((- p) + A)) ) assume x in (- p) + A ; ::_thesis: x in Up (Lin ((- p) + A)) then x in Lin ((- p) + A) by RLVECT_3:15; hence x in Up (Lin ((- p) + A)) by STRUCT_0:def_5; ::_thesis: verum end; then (- p) + I c= Up (Lin ((- p) + A)) by A19, XBOOLE_1:1; then reconsider pI0 = ((- p) + I) \ {(0. V)}, pA = (- p) + A as Subset of (Lin ((- p) + A)) by A20, A21, XBOOLE_1:1; ( Lin ((- p) + A) = Lin pA & pI0 c= pA ) by A19, A20, RLVECT_5:20, XBOOLE_1:1; then consider i being linearly-independent Subset of (Lin ((- p) + A)) such that A22: pI0 c= i and A23: i c= pA and A24: Lin i = Lin ((- p) + A) by A18, Th15, RLVECT_5:15; reconsider Ia = i as linearly-independent Subset of V by RLVECT_5:14; set I0 = Ia \/ {(0. V)}; A25: 0. V in {(0. V)} by TARSKI:def_1; not 0. V in Ia by RLVECT_3:6; then ( (Ia \/ {(0. V)}) \ {(0. V)} = Ia & 0. V in Ia \/ {(0. V)} ) by A25, XBOOLE_0:def_3, ZFMISC_1:117; then Ia \/ {(0. V)} is affinely-independent by Th46; then reconsider pI0 = p + (Ia \/ {(0. V)}) as affinely-independent Subset of V ; take pI0 ; ::_thesis: ( I c= pI0 & pI0 c= A & Affin pI0 = Affin A ) A26: (- p) + p = 0. V by RLVECT_1:5; then A27: p + ((- p) + I) = (0. V) + I by Th5 .= I by Th6 ; 0. V in { ((- p) + v) where v is Element of V : v in I } by A17, A26; then (((- p) + I) \ {(0. V)}) \/ {(0. V)} = (- p) + I by ZFMISC_1:116; then A28: (- p) + I c= Ia \/ {(0. V)} by A22, XBOOLE_1:9; hence I c= pI0 by A27, RLTOPSP1:8; ::_thesis: ( pI0 c= A & Affin pI0 = Affin A ) p + ((- p) + I) c= pI0 by A28, RLTOPSP1:8; then A29: p in pI0 by A17, A27; thus pI0 c= A ::_thesis: Affin pI0 = Affin A proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in pI0 or x in A ) assume x in pI0 ; ::_thesis: x in A then consider v being VECTOR of V such that A30: x = p + v and A31: v in Ia \/ {(0. V)} ; percases ( v in Ia or v in {(0. V)} ) by A31, XBOOLE_0:def_3; suppose v in Ia ; ::_thesis: x in A then v in { ((- p) + w) where w is VECTOR of V : w in A } by A23; then consider w being VECTOR of V such that A32: v = (- p) + w and A33: w in A ; x = (p + (- p)) + w by A30, A32, RLVECT_1:def_3 .= (0. V) + w by RLVECT_1:5 .= w by RLVECT_1:4 ; hence x in A by A33; ::_thesis: verum end; suppose v in {(0. V)} ; ::_thesis: x in A then v = 0. V by TARSKI:def_1; then x = p by A30, RLVECT_1:4; hence x in A by A1, A17; ::_thesis: verum end; end; end; A34: pI0 c= Affin pI0 by Lm7; A35: p in A by A1, A17; (- p) + pI0 = (0. V) + (Ia \/ {(0. V)}) by A26, Th5 .= Ia \/ {(0. V)} by Th6 ; hence Affin pI0 = p + (Up (Lin (Ia \/ {(0. V)}))) by A29, A34, Th57 .= p + (Up (Lin Ia)) by Lm9 .= p + (Up (Lin ((- p) + A))) by A24, RLVECT_5:20 .= Affin A by A2, A35, Th57 ; ::_thesis: verum end; end; end; theorem :: RLAFFIN1:61 for V being RealLinearSpace for A, B being finite Subset of V st A is affinely-independent & Affin A = Affin B & card B <= card A holds B is affinely-independent proof let V be RealLinearSpace; ::_thesis: for A, B being finite Subset of V st A is affinely-independent & Affin A = Affin B & card B <= card A holds B is affinely-independent let A, B be finite Subset of V; ::_thesis: ( A is affinely-independent & Affin A = Affin B & card B <= card A implies B is affinely-independent ) assume that A1: A is affinely-independent and A2: Affin A = Affin B and A3: card B <= card A ; ::_thesis: B is affinely-independent percases ( A is empty or not A is empty ) ; suppose A is empty ; ::_thesis: B is affinely-independent then B is empty by A3, XXREAL_0:1; hence B is affinely-independent ; ::_thesis: verum end; suppose not A is empty ; ::_thesis: B is affinely-independent then consider p being set such that A4: p in A by XBOOLE_0:def_1; card A > 0 by A4; then reconsider n = (card A) - 1 as Element of NAT by NAT_1:20; A5: A c= Affin A by Lm7; reconsider p = p as Element of V by A4; set L = Lin ((- p) + A); {} V c= B by XBOOLE_1:2; then consider Ia being affinely-independent Subset of V such that {} V c= Ia and A6: Ia c= B and A7: Affin Ia = Affin B by Th60; not Ia is empty by A2, A4, A7; then consider q being set such that A8: q in Ia by XBOOLE_0:def_1; (- p) + A c= [#] (Lin ((- p) + A)) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in (- p) + A or x in [#] (Lin ((- p) + A)) ) assume x in (- p) + A ; ::_thesis: x in [#] (Lin ((- p) + A)) then x in Lin ((- p) + A) by RLVECT_3:15; hence x in [#] (Lin ((- p) + A)) by STRUCT_0:def_5; ::_thesis: verum end; then reconsider pA = (- p) + A as Subset of (Lin ((- p) + A)) ; ((- p) + A) \ {(0. V)} is linearly-independent by A1, A4, Th41; then A9: pA \ {(0. V)} is linearly-independent by RLVECT_5:15; (- p) + p = 0. V by RLVECT_1:5; then A10: 0. V in pA by A4; then Lin ((- p) + A) = Lin ((((- p) + A) \ {(0. V)}) \/ {(0. V)}) by ZFMISC_1:116 .= Lin (((- p) + A) \ {(0. V)}) by Lm9 .= Lin (pA \ {(0. V)}) by RLVECT_5:20 ; then A11: pA \ {(0. V)} is Basis of Lin ((- p) + A) by A9, RLVECT_3:def_3; reconsider IA = Ia as finite set by A6; A12: Ia c= Affin Ia by Lm7; reconsider q = q as Element of V by A8; p + (Lin ((- p) + A)) = p + (Up (Lin ((- p) + A))) by RUSUB_4:30 .= Affin A by A4, A5, Th57 .= q + (Up (Lin ((- q) + Ia))) by A2, A7, A8, A12, Th57 .= q + (Lin ((- q) + Ia)) by RUSUB_4:30 ; then A13: Lin ((- p) + A) = Lin ((- q) + Ia) by RLSUB_1:69; set qI = (- q) + Ia; A14: (- q) + Ia c= [#] (Lin ((- q) + Ia)) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in (- q) + Ia or x in [#] (Lin ((- q) + Ia)) ) assume x in (- q) + Ia ; ::_thesis: x in [#] (Lin ((- q) + Ia)) then x in Lin ((- q) + Ia) by RLVECT_3:15; hence x in [#] (Lin ((- q) + Ia)) by STRUCT_0:def_5; ::_thesis: verum end; card pA = n + 1 by Th7; then A15: card (pA \ {(0. V)}) = n by A10, STIRL2_1:55; then pA \ {(0. V)} is finite ; then A16: Lin ((- p) + A) is finite-dimensional by A11, RLVECT_5:def_1; reconsider qI = (- q) + Ia as Subset of (Lin ((- q) + Ia)) by A14; ((- q) + Ia) \ {(0. V)} is linearly-independent by A8, Th41; then A17: qI \ {(0. V)} is linearly-independent by RLVECT_5:15; (- q) + q = 0. V by RLVECT_1:5; then A18: 0. V in qI by A8; then Lin ((- q) + Ia) = Lin ((((- q) + Ia) \ {(0. V)}) \/ {(0. V)}) by ZFMISC_1:116 .= Lin (((- q) + Ia) \ {(0. V)}) by Lm9 .= Lin (qI \ {(0. V)}) by RLVECT_5:20 ; then qI \ {(0. V)} is Basis of Lin ((- q) + Ia) by A17, RLVECT_3:def_3; then A19: card (qI \ {(0. V)}) = n by A11, A13, A15, A16, RLVECT_5:25; then ( not 0. V in qI \ {(0. V)} & qI \ {(0. V)} is finite ) by ZFMISC_1:56; then A20: n + 1 = card ((qI \ {(0. V)}) \/ {(0. V)}) by A19, CARD_2:41 .= card qI by A18, ZFMISC_1:116 .= card Ia by Th7 ; card IA <= card B by A6, NAT_1:43; hence B is affinely-independent by A3, A6, A20, CARD_FIN:1, XXREAL_0:1; ::_thesis: verum end; end; end; theorem Th62: :: RLAFFIN1:62 for V being RealLinearSpace for L being Linear_Combination of V holds ( L is convex iff ( sum L = 1 & ( for v being VECTOR of V holds 0 <= L . v ) ) ) proof let V be RealLinearSpace; ::_thesis: for L being Linear_Combination of V holds ( L is convex iff ( sum L = 1 & ( for v being VECTOR of V holds 0 <= L . v ) ) ) let L be Linear_Combination of V; ::_thesis: ( L is convex iff ( sum L = 1 & ( for v being VECTOR of V holds 0 <= L . v ) ) ) hereby ::_thesis: ( sum L = 1 & ( for v being VECTOR of V holds 0 <= L . v ) implies L is convex ) assume L is convex ; ::_thesis: ( sum L = 1 & ( for v being Element of V holds L . b2 >= 0 ) ) then consider F being FinSequence of the carrier of V such that A1: F is one-to-one and A2: rng F = Carrier L and A3: ex f being FinSequence of REAL st ( len f = len F & Sum f = 1 & ( for n being Nat st n in dom f holds ( f . n = L . (F . n) & f . n >= 0 ) ) ) by CONVEX1:def_3; consider f being FinSequence of REAL such that A4: len f = len F and A5: Sum f = 1 and A6: for n being Nat st n in dom f holds ( f . n = L . (F . n) & f . n >= 0 ) by A3; A7: len (L * F) = len F by FINSEQ_2:33; now__::_thesis:_for_k_being_Nat_st_1_<=_k_&_k_<=_len_F_holds_ (L_*_F)_._k_=_f_._k let k be Nat; ::_thesis: ( 1 <= k & k <= len F implies (L * F) . k = f . k ) assume A8: ( 1 <= k & k <= len F ) ; ::_thesis: (L * F) . k = f . k then k in dom f by A4, FINSEQ_3:25; then A9: f . k = L . (F . k) by A6; k in dom (L * F) by A7, A8, FINSEQ_3:25; hence (L * F) . k = f . k by A9, FUNCT_1:12; ::_thesis: verum end; then L * F = f by A4, A7, FINSEQ_1:14; hence sum L = 1 by A1, A2, A5, Def3; ::_thesis: for v being Element of V holds L . b2 >= 0 let v be Element of V; ::_thesis: L . b1 >= 0 percases ( v in Carrier L or not v in Carrier L ) ; suppose v in Carrier L ; ::_thesis: L . b1 >= 0 then consider n being set such that A10: n in dom F and A11: F . n = v by A2, FUNCT_1:def_3; A12: dom f = dom F by A4, FINSEQ_3:29; then f . n = L . (F . n) by A6, A10; hence L . v >= 0 by A6, A10, A11, A12; ::_thesis: verum end; suppose not v in Carrier L ; ::_thesis: L . b1 >= 0 hence L . v >= 0 ; ::_thesis: verum end; end; end; assume sum L = 1 ; ::_thesis: ( ex v being VECTOR of V st not 0 <= L . v or L is convex ) then consider F being FinSequence of V such that A13: ( F is one-to-one & rng F = Carrier L ) and A14: 1 = Sum (L * F) by Def3; assume A15: for v being Element of V holds L . v >= 0 ; ::_thesis: L is convex now__::_thesis:_ex_F_being_FinSequence_of_V_st_ (_F_is_one-to-one_&_rng_F_=_Carrier_L_&_ex_f_being_FinSequence_of_REAL_st_ (_len_f_=_len_F_&_Sum_f_=_1_&_(_for_n_being_Nat_st_n_in_dom_f_holds_ (_f_._n_=_L_._(F_._n)_&_f_._n_>=_0_)_)_)_) take F = F; ::_thesis: ( F is one-to-one & rng F = Carrier L & ex f being FinSequence of REAL st ( len f = len F & Sum f = 1 & ( for n being Nat st n in dom f holds ( f . n = L . (F . n) & f . n >= 0 ) ) ) ) thus ( F is one-to-one & rng F = Carrier L ) by A13; ::_thesis: ex f being FinSequence of REAL st ( len f = len F & Sum f = 1 & ( for n being Nat st n in dom f holds ( f . n = L . (F . n) & f . n >= 0 ) ) ) take f = L * F; ::_thesis: ( len f = len F & Sum f = 1 & ( for n being Nat st n in dom f holds ( f . n = L . (F . n) & f . n >= 0 ) ) ) thus ( len f = len F & Sum f = 1 ) by A14, FINSEQ_2:33; ::_thesis: for n being Nat st n in dom f holds ( f . n = L . (F . n) & f . n >= 0 ) then A16: dom F = dom f by FINSEQ_3:29; let n be Nat; ::_thesis: ( n in dom f implies ( f . n = L . (F . n) & f . n >= 0 ) ) assume A17: n in dom f ; ::_thesis: ( f . n = L . (F . n) & f . n >= 0 ) then A18: f . n = L . (F . n) by FUNCT_1:12; F . n = F /. n by A16, A17, PARTFUN1:def_6; hence ( f . n = L . (F . n) & f . n >= 0 ) by A15, A18; ::_thesis: verum end; hence L is convex by CONVEX1:def_3; ::_thesis: verum end; theorem Th63: :: RLAFFIN1:63 for x being set for V being RealLinearSpace for L being Linear_Combination of V st L is convex holds L . x <= 1 proof let x be set ; ::_thesis: for V being RealLinearSpace for L being Linear_Combination of V st L is convex holds L . x <= 1 let V be RealLinearSpace; ::_thesis: for L being Linear_Combination of V st L is convex holds L . x <= 1 let L be Linear_Combination of V; ::_thesis: ( L is convex implies L . x <= 1 ) assume A1: L is convex ; ::_thesis: L . x <= 1 then sum L = 1 by Th62; then consider F being FinSequence of V such that F is one-to-one and A2: rng F = Carrier L and A3: 1 = Sum (L * F) by Def3; assume A4: L . x > 1 ; ::_thesis: contradiction then x in dom L by FUNCT_1:def_2; then reconsider v = x as Element of V by FUNCT_2:def_1; v in Carrier L by A4; then consider n being set such that A5: n in dom F and A6: F . n = v by A2, FUNCT_1:def_3; len (L * F) = len F by FINSEQ_2:33; then A7: dom (L * F) = dom F by FINSEQ_3:29; A8: now__::_thesis:_for_i_being_Nat_st_i_in_dom_(L_*_F)_holds_ (L_*_F)_._i_>=_0 let i be Nat; ::_thesis: ( i in dom (L * F) implies (L * F) . i >= 0 ) assume i in dom (L * F) ; ::_thesis: (L * F) . i >= 0 then ( (L * F) . i = L . (F . i) & F . i = F /. i ) by A7, FUNCT_1:12, PARTFUN1:def_6; hence (L * F) . i >= 0 by A1, Th62; ::_thesis: verum end; reconsider n = n as Nat by A5; (L * F) . n = L . x by A5, A6, A7, FUNCT_1:12; hence contradiction by A3, A4, A5, A7, A8, MATRPROB:5; ::_thesis: verum end; theorem Th64: :: RLAFFIN1:64 for x being set for V being RealLinearSpace for L being Linear_Combination of V st L is convex & L . x = 1 holds Carrier L = {x} proof let x be set ; ::_thesis: for V being RealLinearSpace for L being Linear_Combination of V st L is convex & L . x = 1 holds Carrier L = {x} let V be RealLinearSpace; ::_thesis: for L being Linear_Combination of V st L is convex & L . x = 1 holds Carrier L = {x} let L be Linear_Combination of V; ::_thesis: ( L is convex & L . x = 1 implies Carrier L = {x} ) assume that A1: L is convex and A2: L . x = 1 ; ::_thesis: Carrier L = {x} x in dom L by A2, FUNCT_1:def_2; then reconsider v = x as Element of V by FUNCT_2:def_1; consider K being Linear_Combination of {v} such that A3: K . v = 1 by RLVECT_4:37; set LK = L - K; A4: Carrier K c= {v} by RLVECT_2:def_6; sum (L - K) = (sum L) - (sum K) by Th36 .= (sum L) - 1 by A3, A4, Th32 .= 1 - 1 by A1, Th62 .= 0 ; then consider F being FinSequence of V such that F is one-to-one and A5: rng F = Carrier (L - K) and A6: 0 = Sum ((L - K) * F) by Def3; len ((L - K) * F) = len F by FINSEQ_2:33; then A7: dom ((L - K) * F) = dom F by FINSEQ_3:29; A8: for i being Nat st i in dom ((L - K) * F) holds 0 <= ((L - K) * F) . i proof let i be Nat; ::_thesis: ( i in dom ((L - K) * F) implies 0 <= ((L - K) * F) . i ) assume A9: i in dom ((L - K) * F) ; ::_thesis: 0 <= ((L - K) * F) . i then A10: ((L - K) * F) . i = (L - K) . (F . i) by FUNCT_1:12; A11: F . i in Carrier (L - K) by A5, A7, A9, FUNCT_1:def_3; then A12: (L - K) . (F . i) = (L . (F . i)) - (K . (F . i)) by RLVECT_2:54; percases ( F . i = v or F . i <> v ) ; suppose F . i = v ; ::_thesis: 0 <= ((L - K) * F) . i hence 0 <= ((L - K) * F) . i by A2, A3, A9, A12, FUNCT_1:12; ::_thesis: verum end; suppose F . i <> v ; ::_thesis: 0 <= ((L - K) * F) . i then not F . i in Carrier K by A4, TARSKI:def_1; then K . (F . i) = 0 by A11; hence 0 <= ((L - K) * F) . i by A1, A10, A11, A12, Th62; ::_thesis: verum end; end; end; Carrier (L - K) = {} proof assume Carrier (L - K) <> {} ; ::_thesis: contradiction then consider p being set such that A13: p in Carrier (L - K) by XBOOLE_0:def_1; reconsider p = p as Element of V by A13; consider i being set such that A14: i in dom F and A15: F . i = p by A5, A13, FUNCT_1:def_3; reconsider i = i as Nat by A14; ((L - K) * F) . i > 0 proof A16: (L - K) . p = (L . p) - (K . p) by RLVECT_2:54; percases ( p = v or p <> v ) ; suppose p = v ; ::_thesis: ((L - K) * F) . i > 0 then (L - K) . p = 1 - 1 by A2, A3, RLVECT_2:54; hence ((L - K) * F) . i > 0 by A13, RLVECT_2:19; ::_thesis: verum end; suppose p <> v ; ::_thesis: ((L - K) * F) . i > 0 then not p in Carrier K by A4, TARSKI:def_1; then K . p = 0 ; then A17: (L - K) . p >= 0 by A1, A16, Th62; (L - K) . p <> 0 by A13, RLVECT_2:19; hence ((L - K) * F) . i > 0 by A7, A14, A15, A17, FUNCT_1:12; ::_thesis: verum end; end; end; hence contradiction by A6, A7, A8, A14, RVSUM_1:85; ::_thesis: verum end; then ZeroLC V = L + (- K) by RLVECT_2:def_5; then A18: - K = - L by RLVECT_2:50; A19: v in Carrier L by A2; - (- L) = L by RLVECT_2:53; then K = L by A18, RLVECT_2:53; hence Carrier L = {x} by A4, A19, ZFMISC_1:33; ::_thesis: verum end; theorem Th65: :: RLAFFIN1:65 for V being RealLinearSpace for A being Subset of V holds conv A c= Affin A proof let V be RealLinearSpace; ::_thesis: for A being Subset of V holds conv A c= Affin A let A be Subset of V; ::_thesis: conv A c= Affin A let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in conv A or x in Affin A ) assume A1: x in conv A ; ::_thesis: x in Affin A then reconsider A1 = A as non empty Subset of V ; conv A1 = { (Sum L) where L is Convex_Combination of A1 : L in ConvexComb V } by CONVEX3:5; then consider L being Convex_Combination of A1 such that A2: Sum L = x and L in ConvexComb V by A1; sum L = 1 by Th62; then x in { (Sum K) where K is Linear_Combination of A : sum K = 1 } by A2; hence x in Affin A by Th59; ::_thesis: verum end; theorem :: RLAFFIN1:66 for x being set for V being RealLinearSpace for A being Subset of V st x in conv A & (conv A) \ {x} is convex holds x in A proof let x be set ; ::_thesis: for V being RealLinearSpace for A being Subset of V st x in conv A & (conv A) \ {x} is convex holds x in A let V be RealLinearSpace; ::_thesis: for A being Subset of V st x in conv A & (conv A) \ {x} is convex holds x in A let A be Subset of V; ::_thesis: ( x in conv A & (conv A) \ {x} is convex implies x in A ) assume that A1: x in conv A and A2: (conv A) \ {x} is convex ; ::_thesis: x in A reconsider A1 = A as non empty Subset of V by A1; A3: conv A1 = { (Sum L) where L is Convex_Combination of A1 : L in ConvexComb V } by CONVEX3:5; assume A4: not x in A ; ::_thesis: contradiction consider L being Convex_Combination of A1 such that A5: Sum L = x and L in ConvexComb V by A1, A3; set C = Carrier L; A6: Carrier L c= A1 by RLVECT_2:def_6; Carrier L <> {} by CONVEX1:21; then consider p being set such that A7: p in Carrier L by XBOOLE_0:def_1; reconsider p = p as Element of V by A7; A8: sum L = 1 by Th62; (Carrier L) \ {p} <> {} proof assume A9: (Carrier L) \ {p} = {} ; ::_thesis: contradiction then Carrier L = {p} by A7, ZFMISC_1:58; then A10: L . p = 1 by A8, Th32; Sum L = (L . p) * p by A7, A9, RLVECT_2:35, ZFMISC_1:58; then x = p by A5, A10, RLVECT_1:def_8; hence contradiction by A4, A6, A7; ::_thesis: verum end; then consider q being set such that A11: q in (Carrier L) \ {p} by XBOOLE_0:def_1; reconsider q = q as Element of V by A11; A12: q in Carrier L by A11, XBOOLE_0:def_5; then L . q <> 0 by RLVECT_2:19; then A13: L . q > 0 by Th62; reconsider mm = min ((L . p),(L . q)) as Real by XREAL_0:def_1; consider Lq being Linear_Combination of {q} such that A14: Lq . q = mm by RLVECT_4:37; A15: p <> q by A11, ZFMISC_1:56; then A16: p - q <> 0. V by RLVECT_1:21; A17: Carrier Lq c= {q} by RLVECT_2:def_6; {q} c= A by A6, A12, ZFMISC_1:31; then Carrier Lq c= A by A17, XBOOLE_1:1; then A18: Lq is Linear_Combination of A by RLVECT_2:def_6; consider Lp being Linear_Combination of {p} such that A19: Lp . p = mm by RLVECT_4:37; A20: Carrier Lp c= {p} by RLVECT_2:def_6; {p} c= A by A6, A7, ZFMISC_1:31; then Carrier Lp c= A by A20, XBOOLE_1:1; then Lp is Linear_Combination of A by RLVECT_2:def_6; then A21: Lp - Lq is Linear_Combination of A by A18, RLVECT_2:56; then - (Lp - Lq) is Linear_Combination of A by RLVECT_2:52; then reconsider Lpq = L + (Lp - Lq), L1pq = L - (Lp - Lq) as Linear_Combination of A1 by A21, RLVECT_2:38; A22: Sum L1pq = (Sum L) - (Sum (Lp - Lq)) by RLVECT_3:4 .= (Sum L) + (- (Sum (Lp - Lq))) by RLVECT_1:def_11 ; L . p <> 0 by A7, RLVECT_2:19; then L . p > 0 by Th62; then A23: mm > 0 by A13, XXREAL_0:15; A24: for v being VECTOR of V holds L1pq . v >= 0 proof let v be VECTOR of V; ::_thesis: L1pq . v >= 0 A25: L1pq . v = (L . v) - ((Lp - Lq) . v) by RLVECT_2:54 .= (L . v) - ((Lp . v) - (Lq . v)) by RLVECT_2:54 ; A26: L . v >= 0 by Th62; percases ( v = q or v = p or ( v <> p & v <> q ) ) ; supposeA27: v = q ; ::_thesis: L1pq . v >= 0 then not v in Carrier Lp by A15, A20, TARSKI:def_1; then Lp . v = 0 ; hence L1pq . v >= 0 by A23, A14, A25, A26, A27; ::_thesis: verum end; supposeA28: v = p ; ::_thesis: L1pq . v >= 0 L . p >= mm by XXREAL_0:17; then A29: (L . p) - mm >= mm - mm by XREAL_1:9; not v in Carrier Lq by A15, A17, A28, TARSKI:def_1; then Lq . v = 0 ; hence L1pq . v >= 0 by A19, A25, A28, A29; ::_thesis: verum end; supposeA30: ( v <> p & v <> q ) ; ::_thesis: L1pq . v >= 0 then not v in Carrier Lq by A17, TARSKI:def_1; then A31: Lq . v = 0 ; not v in Carrier Lp by A20, A30, TARSKI:def_1; then Lp . v = 0 ; hence L1pq . v >= 0 by A25, A31, Th62; ::_thesis: verum end; end; end; Sum (Lp - Lq) = (Sum Lp) - (Sum Lq) by RLVECT_3:4 .= (mm * p) - (Sum Lq) by A19, RLVECT_2:32 .= (mm * p) - (mm * q) by A14, RLVECT_2:32 .= mm * (p - q) by RLVECT_1:34 ; then A32: Sum (Lp - Lq) <> 0. V by A23, A16, RLVECT_1:11; A33: sum (Lp - Lq) = (sum Lp) - (sum Lq) by Th36 .= mm - (sum Lq) by A19, A20, Th32 .= mm - mm by A14, A17, Th32 .= 0 ; A34: for v being VECTOR of V holds Lpq . v >= 0 proof let v be VECTOR of V; ::_thesis: Lpq . v >= 0 A35: Lpq . v = (L . v) + ((Lp - Lq) . v) by RLVECT_2:def_10 .= (L . v) + ((Lp . v) - (Lq . v)) by RLVECT_2:54 ; A36: L . v >= 0 by Th62; percases ( v = p or v = q or ( v <> p & v <> q ) ) ; supposeA37: v = p ; ::_thesis: Lpq . v >= 0 then not v in Carrier Lq by A15, A17, TARSKI:def_1; then Lpq . v = (L . v) + (mm - 0) by A19, A35, A37; hence Lpq . v >= 0 by A23, A36; ::_thesis: verum end; supposeA38: v = q ; ::_thesis: Lpq . v >= 0 L . q >= mm by XXREAL_0:17; then A39: (L . q) - mm >= mm - mm by XREAL_1:9; not v in Carrier Lp by A15, A20, A38, TARSKI:def_1; then Lp . v = 0 ; hence Lpq . v >= 0 by A14, A35, A38, A39; ::_thesis: verum end; supposeA40: ( v <> p & v <> q ) ; ::_thesis: Lpq . v >= 0 then not v in Carrier Lq by A17, TARSKI:def_1; then A41: Lq . v = 0 ; not v in Carrier Lp by A20, A40, TARSKI:def_1; then Lp . v = 0 ; hence Lpq . v >= 0 by A35, A41, Th62; ::_thesis: verum end; end; end; sum L1pq = (sum L) - (sum (Lp - Lq)) by Th36 .= 1 + 0 by A33, Th62 ; then A42: L1pq is convex by A24, Th62; then L1pq in ConvexComb V by CONVEX3:def_1; then A43: Sum L1pq in conv A1 by A3, A42; sum Lpq = (sum L) + (sum (Lp - Lq)) by Th34 .= 1 + 0 by A33, Th62 ; then A44: Lpq is convex by A34, Th62; then Lpq in ConvexComb V by CONVEX3:def_1; then A45: Sum Lpq in conv A by A3, A44; 0. V = - (0. V) by RLVECT_1:12; then - (Sum (Lp - Lq)) <> 0. V by A32, RLVECT_1:18; then Sum L1pq <> x by A5, A22, RLVECT_1:9; then A46: Sum L1pq in (conv A) \ {x} by A43, ZFMISC_1:56; Sum Lpq = (Sum L) + (Sum (Lp - Lq)) by RLVECT_3:1; then Sum Lpq <> x by A5, A32, RLVECT_1:9; then A47: Sum Lpq in (conv A) \ {x} by A45, ZFMISC_1:56; ((1 / 2) * (Sum Lpq)) + ((1 - (1 / 2)) * (Sum L1pq)) = ((1 / 2) * ((Sum L) + (Sum (Lp - Lq)))) + ((1 / 2) * ((Sum L) + (- (Sum (Lp - Lq))))) by A22, RLVECT_3:1 .= (((1 / 2) * (Sum L)) + ((1 / 2) * (Sum (Lp - Lq)))) + ((1 / 2) * ((Sum L) + (- (Sum (Lp - Lq))))) by RLVECT_1:def_5 .= (((1 / 2) * (Sum L)) + ((1 / 2) * (Sum (Lp - Lq)))) + (((1 / 2) * (Sum L)) + ((1 / 2) * (- (Sum (Lp - Lq))))) by RLVECT_1:def_5 .= ((1 / 2) * (Sum L)) + (((1 / 2) * (Sum (Lp - Lq))) + (((1 / 2) * (- (Sum (Lp - Lq)))) + ((1 / 2) * (Sum L)))) by RLVECT_1:def_3 .= ((1 / 2) * (Sum L)) + ((((1 / 2) * (Sum (Lp - Lq))) + ((1 / 2) * (- (Sum (Lp - Lq))))) + ((1 / 2) * (Sum L))) by RLVECT_1:def_3 .= ((1 / 2) * (Sum L)) + (((1 / 2) * ((Sum (Lp - Lq)) + (- (Sum (Lp - Lq))))) + ((1 / 2) * (Sum L))) by RLVECT_1:def_5 .= ((1 / 2) * (Sum L)) + (((1 / 2) * (0. V)) + ((1 / 2) * (Sum L))) by RLVECT_1:5 .= ((1 / 2) * (Sum L)) + ((0. V) + ((1 / 2) * (Sum L))) by RLVECT_1:10 .= ((1 / 2) * (Sum L)) + ((1 / 2) * (Sum L)) by RLVECT_1:def_4 .= ((1 / 2) + (1 / 2)) * (Sum L) by RLVECT_1:def_6 .= Sum L by RLVECT_1:def_8 ; then Sum L in (conv A) \ {x} by A2, A46, A47, CONVEX1:def_2; hence contradiction by A5, ZFMISC_1:56; ::_thesis: verum end; theorem Th67: :: RLAFFIN1:67 for V being RealLinearSpace for A being Subset of V holds Affin (conv A) = Affin A proof let V be RealLinearSpace; ::_thesis: for A being Subset of V holds Affin (conv A) = Affin A let A be Subset of V; ::_thesis: Affin (conv A) = Affin A thus Affin (conv A) c= Affin A by Th51, Th65; :: according to XBOOLE_0:def_10 ::_thesis: Affin A c= Affin (conv A) let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in Affin A or x in Affin (conv A) ) assume x in Affin A ; ::_thesis: x in Affin (conv A) then x in { (Sum L) where L is Linear_Combination of A : sum L = 1 } by Th59; then consider L being Linear_Combination of A such that A1: x = Sum L and A2: sum L = 1 ; reconsider K = L as Linear_Combination of conv A by Lm1, RLVECT_2:21; Sum K in { (Sum M) where M is Linear_Combination of conv A : sum M = 1 } by A2; hence x in Affin (conv A) by A1, Th59; ::_thesis: verum end; theorem :: RLAFFIN1:68 for V being RealLinearSpace for A, B being Subset of V st conv A c= conv B holds Affin A c= Affin B proof let V be RealLinearSpace; ::_thesis: for A, B being Subset of V st conv A c= conv B holds Affin A c= Affin B let A, B be Subset of V; ::_thesis: ( conv A c= conv B implies Affin A c= Affin B ) ( Affin (conv A) = Affin A & Affin (conv B) = Affin B ) by Th67; hence ( conv A c= conv B implies Affin A c= Affin B ) by Th52; ::_thesis: verum end; theorem Th69: :: RLAFFIN1:69 for RLS being non empty RLSStruct for A, B being Subset of RLS st A c= Affin B holds Affin (A \/ B) = Affin B proof let RLS be non empty RLSStruct ; ::_thesis: for A, B being Subset of RLS st A c= Affin B holds Affin (A \/ B) = Affin B let A, B be Subset of RLS; ::_thesis: ( A c= Affin B implies Affin (A \/ B) = Affin B ) assume A1: A c= Affin B ; ::_thesis: Affin (A \/ B) = Affin B set AB = { C where C is Affine Subset of RLS : A \/ B c= C } ; B c= Affin B by Lm7; then A \/ B c= Affin B by A1, XBOOLE_1:8; then Affin B in { C where C is Affine Subset of RLS : A \/ B c= C } ; then A2: Affin (A \/ B) c= Affin B by SETFAM_1:3; Affin B c= Affin (A \/ B) by Th52, XBOOLE_1:7; hence Affin (A \/ B) = Affin B by A2, XBOOLE_0:def_10; ::_thesis: verum end; begin definition let V be RealLinearSpace; let A be Subset of V; assume B1: A is affinely-independent ; let x be set ; assume B2: x in Affin A ; funcx |-- A -> Linear_Combination of A means :Def7: :: RLAFFIN1:def 7 ( Sum it = x & sum it = 1 ); existence ex b1 being Linear_Combination of A st ( Sum b1 = x & sum b1 = 1 ) proof Affin A = { (Sum L) where L is Linear_Combination of A : sum L = 1 } by Th59; hence ex b1 being Linear_Combination of A st ( Sum b1 = x & sum b1 = 1 ) by B2; ::_thesis: verum end; uniqueness for b1, b2 being Linear_Combination of A st Sum b1 = x & sum b1 = 1 & Sum b2 = x & sum b2 = 1 holds b1 = b2 proof let L1, L2 be Linear_Combination of A; ::_thesis: ( Sum L1 = x & sum L1 = 1 & Sum L2 = x & sum L2 = 1 implies L1 = L2 ) assume that A1: Sum L1 = x and A2: sum L1 = 1 and A3: Sum L2 = x and A4: sum L2 = 1 ; ::_thesis: L1 = L2 A5: Sum (L1 - L2) = (Sum L1) - (Sum L1) by A1, A3, RLVECT_3:4 .= 0. V by RLVECT_1:15 ; A6: L1 - L2 is Linear_Combination of A by RLVECT_2:56; sum (L1 - L2) = 1 - 1 by A2, A4, Th36 .= 0 ; then Carrier (L1 - L2) = {} by B1, A5, A6, Th42; then ZeroLC V = L1 + (- L2) by RLVECT_2:def_5; then A7: - L2 = - L1 by RLVECT_2:50; L1 = - (- L1) by RLVECT_2:53; hence L1 = L2 by A7, RLVECT_2:53; ::_thesis: verum end; end; :: deftheorem Def7 defines |-- RLAFFIN1:def_7_:_ for V being RealLinearSpace for A being Subset of V st A is affinely-independent holds for x being set st x in Affin A holds for b4 being Linear_Combination of A holds ( b4 = x |-- A iff ( Sum b4 = x & sum b4 = 1 ) ); theorem Th70: :: RLAFFIN1:70 for r being Real for V being RealLinearSpace for v1, v2 being VECTOR of V for I being affinely-independent Subset of V st v1 in Affin I & v2 in Affin I holds (((1 - r) * v1) + (r * v2)) |-- I = ((1 - r) * (v1 |-- I)) + (r * (v2 |-- I)) proof let r be Real; ::_thesis: for V being RealLinearSpace for v1, v2 being VECTOR of V for I being affinely-independent Subset of V st v1 in Affin I & v2 in Affin I holds (((1 - r) * v1) + (r * v2)) |-- I = ((1 - r) * (v1 |-- I)) + (r * (v2 |-- I)) let V be RealLinearSpace; ::_thesis: for v1, v2 being VECTOR of V for I being affinely-independent Subset of V st v1 in Affin I & v2 in Affin I holds (((1 - r) * v1) + (r * v2)) |-- I = ((1 - r) * (v1 |-- I)) + (r * (v2 |-- I)) let v1, v2 be VECTOR of V; ::_thesis: for I being affinely-independent Subset of V st v1 in Affin I & v2 in Affin I holds (((1 - r) * v1) + (r * v2)) |-- I = ((1 - r) * (v1 |-- I)) + (r * (v2 |-- I)) let I be affinely-independent Subset of V; ::_thesis: ( v1 in Affin I & v2 in Affin I implies (((1 - r) * v1) + (r * v2)) |-- I = ((1 - r) * (v1 |-- I)) + (r * (v2 |-- I)) ) assume that A1: v1 in Affin I and A2: v2 in Affin I ; ::_thesis: (((1 - r) * v1) + (r * v2)) |-- I = ((1 - r) * (v1 |-- I)) + (r * (v2 |-- I)) set rv12 = ((1 - r) * v1) + (r * v2); A3: ((1 - r) * v1) + (r * v2) in Affin I by A1, A2, RUSUB_4:def_4; ( (1 - r) * (v1 |-- I) is Linear_Combination of I & r * (v2 |-- I) is Linear_Combination of I ) by RLVECT_2:44; then A4: ((1 - r) * (v1 |-- I)) + (r * (v2 |-- I)) is Linear_Combination of I by RLVECT_2:38; A5: Sum (((1 - r) * (v1 |-- I)) + (r * (v2 |-- I))) = (Sum ((1 - r) * (v1 |-- I))) + (Sum (r * (v2 |-- I))) by RLVECT_3:1 .= ((1 - r) * (Sum (v1 |-- I))) + (Sum (r * (v2 |-- I))) by RLVECT_3:2 .= ((1 - r) * (Sum (v1 |-- I))) + (r * (Sum (v2 |-- I))) by RLVECT_3:2 .= ((1 - r) * v1) + (r * (Sum (v2 |-- I))) by A1, Def7 .= ((1 - r) * v1) + (r * v2) by A2, Def7 ; sum (((1 - r) * (v1 |-- I)) + (r * (v2 |-- I))) = (sum ((1 - r) * (v1 |-- I))) + (sum (r * (v2 |-- I))) by Th34 .= ((1 - r) * (sum (v1 |-- I))) + (sum (r * (v2 |-- I))) by Th35 .= ((1 - r) * (sum (v1 |-- I))) + (r * (sum (v2 |-- I))) by Th35 .= ((1 - r) * 1) + (r * (sum (v2 |-- I))) by A1, Def7 .= ((1 - r) * 1) + (r * 1) by A2, Def7 .= 1 ; hence (((1 - r) * v1) + (r * v2)) |-- I = ((1 - r) * (v1 |-- I)) + (r * (v2 |-- I)) by A3, A4, A5, Def7; ::_thesis: verum end; theorem Th71: :: RLAFFIN1:71 for x being set for V being RealLinearSpace for v being VECTOR of V for I being affinely-independent Subset of V st x in conv I holds ( x |-- I is convex & 0 <= (x |-- I) . v & (x |-- I) . v <= 1 ) proof let x be set ; ::_thesis: for V being RealLinearSpace for v being VECTOR of V for I being affinely-independent Subset of V st x in conv I holds ( x |-- I is convex & 0 <= (x |-- I) . v & (x |-- I) . v <= 1 ) let V be RealLinearSpace; ::_thesis: for v being VECTOR of V for I being affinely-independent Subset of V st x in conv I holds ( x |-- I is convex & 0 <= (x |-- I) . v & (x |-- I) . v <= 1 ) let v be VECTOR of V; ::_thesis: for I being affinely-independent Subset of V st x in conv I holds ( x |-- I is convex & 0 <= (x |-- I) . v & (x |-- I) . v <= 1 ) let I be affinely-independent Subset of V; ::_thesis: ( x in conv I implies ( x |-- I is convex & 0 <= (x |-- I) . v & (x |-- I) . v <= 1 ) ) assume A1: x in conv I ; ::_thesis: ( x |-- I is convex & 0 <= (x |-- I) . v & (x |-- I) . v <= 1 ) then reconsider I1 = I as non empty Subset of V ; conv I1 = { (Sum L) where L is Convex_Combination of I1 : L in ConvexComb V } by CONVEX3:5; then consider L being Convex_Combination of I1 such that A2: Sum L = x and L in ConvexComb V by A1; ( conv I c= Affin I & sum L = 1 ) by Th62, Th65; then L = x |-- I by A1, A2, Def7; hence ( x |-- I is convex & 0 <= (x |-- I) . v & (x |-- I) . v <= 1 ) by Th62, Th63; ::_thesis: verum end; theorem Th72: :: RLAFFIN1:72 for x, y being set for V being RealLinearSpace for I being affinely-independent Subset of V st x in conv I holds ( (x |-- I) . y = 1 iff ( x = y & x in I ) ) proof let x, y be set ; ::_thesis: for V being RealLinearSpace for I being affinely-independent Subset of V st x in conv I holds ( (x |-- I) . y = 1 iff ( x = y & x in I ) ) let V be RealLinearSpace; ::_thesis: for I being affinely-independent Subset of V st x in conv I holds ( (x |-- I) . y = 1 iff ( x = y & x in I ) ) let I be affinely-independent Subset of V; ::_thesis: ( x in conv I implies ( (x |-- I) . y = 1 iff ( x = y & x in I ) ) ) assume A1: x in conv I ; ::_thesis: ( (x |-- I) . y = 1 iff ( x = y & x in I ) ) then reconsider v = x as Element of V ; hereby ::_thesis: ( x = y & x in I implies (x |-- I) . y = 1 ) assume A2: (x |-- I) . y = 1 ; ::_thesis: ( x = y & x in I ) x |-- I is convex by A1, Th71; then A3: Carrier (x |-- I) = {y} by A2, Th64; y in {y} by TARSKI:def_1; then reconsider v = y as Element of V by A3; conv I c= Affin I by Th65; hence A4: x = Sum (x |-- I) by A1, Def7 .= ((x |-- I) . v) * v by A3, RLVECT_2:35 .= y by A2, RLVECT_1:def_8 ; ::_thesis: x in I ( Carrier (x |-- I) c= I & v in Carrier (x |-- I) ) by A2, RLVECT_2:def_6; hence x in I by A4; ::_thesis: verum end; assume that A5: x = y and A6: x in I ; ::_thesis: (x |-- I) . y = 1 consider L being Linear_Combination of {v} such that A7: L . v = 1 by RLVECT_4:37; Carrier L c= {v} by RLVECT_2:def_6; then A8: sum L = 1 by A7, Th32; A9: I c= Affin I by Lm7; {v} c= I by A6, ZFMISC_1:31; then A10: L is Linear_Combination of I by RLVECT_2:21; Sum L = 1 * v by A7, RLVECT_2:32 .= v by RLVECT_1:def_8 ; hence (x |-- I) . y = 1 by A5, A6, A7, A8, A9, A10, Def7; ::_thesis: verum end; theorem Th73: :: RLAFFIN1:73 for x being set for V being RealLinearSpace for I being affinely-independent Subset of V st x in Affin I & ( for v being VECTOR of V st v in I holds 0 <= (x |-- I) . v ) holds x in conv I proof let x be set ; ::_thesis: for V being RealLinearSpace for I being affinely-independent Subset of V st x in Affin I & ( for v being VECTOR of V st v in I holds 0 <= (x |-- I) . v ) holds x in conv I let V be RealLinearSpace; ::_thesis: for I being affinely-independent Subset of V st x in Affin I & ( for v being VECTOR of V st v in I holds 0 <= (x |-- I) . v ) holds x in conv I let I be affinely-independent Subset of V; ::_thesis: ( x in Affin I & ( for v being VECTOR of V st v in I holds 0 <= (x |-- I) . v ) implies x in conv I ) assume that A1: x in Affin I and A2: for v being VECTOR of V st v in I holds 0 <= (x |-- I) . v ; ::_thesis: x in conv I set xI = x |-- I; A3: Sum (x |-- I) = x by A1, Def7; reconsider I1 = I as non empty Subset of V by A1; A4: for v being VECTOR of V holds 0 <= (x |-- I) . v proof let v be VECTOR of V; ::_thesis: 0 <= (x |-- I) . v A5: ( v in Carrier (x |-- I) or not v in Carrier (x |-- I) ) ; Carrier (x |-- I) c= I by RLVECT_2:def_6; hence 0 <= (x |-- I) . v by A2, A5; ::_thesis: verum end; sum (x |-- I) = 1 by A1, Def7; then A6: x |-- I is convex by A4, Th62; then ( conv I1 = { (Sum L) where L is Convex_Combination of I1 : L in ConvexComb V } & x |-- I in ConvexComb V ) by CONVEX3:5, CONVEX3:def_1; hence x in conv I by A3, A6; ::_thesis: verum end; theorem :: RLAFFIN1:74 for x being set for V being RealLinearSpace for I being affinely-independent Subset of V st x in I holds (conv I) \ {x} is convex proof let x be set ; ::_thesis: for V being RealLinearSpace for I being affinely-independent Subset of V st x in I holds (conv I) \ {x} is convex let V be RealLinearSpace; ::_thesis: for I being affinely-independent Subset of V st x in I holds (conv I) \ {x} is convex let I be affinely-independent Subset of V; ::_thesis: ( x in I implies (conv I) \ {x} is convex ) assume A1: x in I ; ::_thesis: (conv I) \ {x} is convex then reconsider X = x as Element of V ; A2: conv I c= Affin I by Th65; now__::_thesis:_for_v1,_v2_being_VECTOR_of_V for_r_being_Real_st_0_<_r_&_r_<_1_&_v1_in_(conv_I)_\_{x}_&_v2_in_(conv_I)_\_{x}_holds_ (r_*_v1)_+_((1_-_r)_*_v2)_in_(conv_I)_\_{x} let v1, v2 be VECTOR of V; ::_thesis: for r being Real st 0 < r & r < 1 & v1 in (conv I) \ {x} & v2 in (conv I) \ {x} holds (r * v1) + ((1 - r) * v2) in (conv I) \ {x} let r be Real; ::_thesis: ( 0 < r & r < 1 & v1 in (conv I) \ {x} & v2 in (conv I) \ {x} implies (r * v1) + ((1 - r) * v2) in (conv I) \ {x} ) set rv12 = (r * v1) + ((1 - r) * v2); assume that A3: 0 < r and A4: r < 1 ; ::_thesis: ( v1 in (conv I) \ {x} & v2 in (conv I) \ {x} implies (r * v1) + ((1 - r) * v2) in (conv I) \ {x} ) assume that A5: v1 in (conv I) \ {x} and A6: v2 in (conv I) \ {x} ; ::_thesis: (r * v1) + ((1 - r) * v2) in (conv I) \ {x} A7: 1 - r > 1 - 1 by A4, XREAL_1:10; A8: v2 in conv I by A6, ZFMISC_1:56; then A9: (v2 |-- I) . X <= 1 by Th71; A10: v1 in conv I by A5, ZFMISC_1:56; then A11: (v1 |-- I) . X <= 1 by Th71; A12: ((r * v1) + ((1 - r) * v2)) |-- I = ((1 - r) * (v2 |-- I)) + (r * (v1 |-- I)) by A2, A10, A8, Th70; A13: now__::_thesis:_for_w_being_VECTOR_of_V_st_w_in_I_holds_ 0_<=_(((r_*_v1)_+_((1_-_r)_*_v2))_|--_I)_._w let w be VECTOR of V; ::_thesis: ( w in I implies 0 <= (((r * v1) + ((1 - r) * v2)) |-- I) . w ) assume w in I ; ::_thesis: 0 <= (((r * v1) + ((1 - r) * v2)) |-- I) . w A14: (((r * v1) + ((1 - r) * v2)) |-- I) . w = (((1 - r) * (v2 |-- I)) . w) + ((r * (v1 |-- I)) . w) by A12, RLVECT_2:def_10 .= ((1 - r) * ((v2 |-- I) . w)) + ((r * (v1 |-- I)) . w) by RLVECT_2:def_11 .= ((1 - r) * ((v2 |-- I) . w)) + (r * ((v1 |-- I) . w)) by RLVECT_2:def_11 ; ( (v2 |-- I) . w >= 0 & (v1 |-- I) . w >= 0 ) by A10, A8, Th71; hence 0 <= (((r * v1) + ((1 - r) * v2)) |-- I) . w by A3, A7, A14; ::_thesis: verum end; (r * v1) + ((1 - r) * v2) in Affin I by A2, A10, A8, RUSUB_4:def_4; then A15: (r * v1) + ((1 - r) * v2) in conv I by A13, Th73; v1 <> x by A5, ZFMISC_1:56; then (v1 |-- I) . X <> 1 by A10, Th72; then (v1 |-- I) . X < 1 by A11, XXREAL_0:1; then A16: r * ((v1 |-- I) . X) < r * 1 by A3, XREAL_1:68; v2 <> x by A6, ZFMISC_1:56; then (v2 |-- I) . X <> 1 by A8, Th72; then (v2 |-- I) . X < 1 by A9, XXREAL_0:1; then (1 - r) * ((v2 |-- I) . X) < (1 - r) * 1 by A7, XREAL_1:68; then A17: ((1 - r) * ((v2 |-- I) . X)) + (r * ((v1 |-- I) . X)) < ((1 - r) * 1) + (r * 1) by A16, XREAL_1:8; (((r * v1) + ((1 - r) * v2)) |-- I) . X = (((1 - r) * (v2 |-- I)) . X) + ((r * (v1 |-- I)) . X) by A12, RLVECT_2:def_10 .= ((1 - r) * ((v2 |-- I) . X)) + ((r * (v1 |-- I)) . X) by RLVECT_2:def_11 .= ((1 - r) * ((v2 |-- I) . X)) + (r * ((v1 |-- I) . X)) by RLVECT_2:def_11 ; then (r * v1) + ((1 - r) * v2) <> X by A1, A15, A17, Th72; hence (r * v1) + ((1 - r) * v2) in (conv I) \ {x} by A15, ZFMISC_1:56; ::_thesis: verum end; hence (conv I) \ {x} is convex by CONVEX1:def_2; ::_thesis: verum end; theorem Th75: :: RLAFFIN1:75 for x being set for V being RealLinearSpace for I being affinely-independent Subset of V for B being Subset of V st x in Affin I & ( for y being set st y in B holds (x |-- I) . y = 0 ) holds ( x in Affin (I \ B) & x |-- I = x |-- (I \ B) ) proof let x be set ; ::_thesis: for V being RealLinearSpace for I being affinely-independent Subset of V for B being Subset of V st x in Affin I & ( for y being set st y in B holds (x |-- I) . y = 0 ) holds ( x in Affin (I \ B) & x |-- I = x |-- (I \ B) ) let V be RealLinearSpace; ::_thesis: for I being affinely-independent Subset of V for B being Subset of V st x in Affin I & ( for y being set st y in B holds (x |-- I) . y = 0 ) holds ( x in Affin (I \ B) & x |-- I = x |-- (I \ B) ) let I be affinely-independent Subset of V; ::_thesis: for B being Subset of V st x in Affin I & ( for y being set st y in B holds (x |-- I) . y = 0 ) holds ( x in Affin (I \ B) & x |-- I = x |-- (I \ B) ) let B be Subset of V; ::_thesis: ( x in Affin I & ( for y being set st y in B holds (x |-- I) . y = 0 ) implies ( x in Affin (I \ B) & x |-- I = x |-- (I \ B) ) ) assume that A1: x in Affin I and A2: for y being set st y in B holds (x |-- I) . y = 0 ; ::_thesis: ( x in Affin (I \ B) & x |-- I = x |-- (I \ B) ) A3: Affin I = { (Sum L) where L is Linear_Combination of I : sum L = 1 } by Th59; A4: I \ B is affinely-independent by Th43, XBOOLE_1:36; consider L being Linear_Combination of I such that A5: ( x = Sum L & sum L = 1 ) by A1, A3; A6: x |-- I = L by A1, A5, Def7; Carrier L c= I \ B proof A7: Carrier L c= I by RLVECT_2:def_6; let y be set ; :: according to TARSKI:def_3 ::_thesis: ( not y in Carrier L or y in I \ B ) assume A8: y in Carrier L ; ::_thesis: y in I \ B assume not y in I \ B ; ::_thesis: contradiction then y in B by A7, A8, XBOOLE_0:def_5; then L . y = 0 by A2, A6; hence contradiction by A8, RLVECT_2:19; ::_thesis: verum end; then A9: L is Linear_Combination of I \ B by RLVECT_2:def_6; then x in { (Sum K) where K is Linear_Combination of I \ B : sum K = 1 } by A5; then x in Affin (I \ B) by Th59; hence ( x in Affin (I \ B) & x |-- I = x |-- (I \ B) ) by A4, A5, A6, A9, Def7; ::_thesis: verum end; theorem :: RLAFFIN1:76 for x being set for V being RealLinearSpace for I being affinely-independent Subset of V for B being Subset of V st x in conv I & ( for y being set st y in B holds (x |-- I) . y = 0 ) holds x in conv (I \ B) proof let x be set ; ::_thesis: for V being RealLinearSpace for I being affinely-independent Subset of V for B being Subset of V st x in conv I & ( for y being set st y in B holds (x |-- I) . y = 0 ) holds x in conv (I \ B) let V be RealLinearSpace; ::_thesis: for I being affinely-independent Subset of V for B being Subset of V st x in conv I & ( for y being set st y in B holds (x |-- I) . y = 0 ) holds x in conv (I \ B) let I be affinely-independent Subset of V; ::_thesis: for B being Subset of V st x in conv I & ( for y being set st y in B holds (x |-- I) . y = 0 ) holds x in conv (I \ B) let B be Subset of V; ::_thesis: ( x in conv I & ( for y being set st y in B holds (x |-- I) . y = 0 ) implies x in conv (I \ B) ) assume that A1: x in conv I and A2: for y being set st y in B holds (x |-- I) . y = 0 ; ::_thesis: x in conv (I \ B) set IB = I \ B; A3: conv I c= Affin I by Th65; then x |-- I = x |-- (I \ B) by A1, A2, Th75; then A4: for v being VECTOR of V st v in I \ B holds 0 <= (x |-- (I \ B)) . v by A1, Th71; A5: I \ B is affinely-independent by Th43, XBOOLE_1:36; x in Affin (I \ B) by A1, A2, A3, Th75; hence x in conv (I \ B) by A4, A5, Th73; ::_thesis: verum end; theorem Th77: :: RLAFFIN1:77 for x being set for V being RealLinearSpace for B being Subset of V for I being affinely-independent Subset of V st B c= I & x in Affin B holds x |-- B = x |-- I proof let x be set ; ::_thesis: for V being RealLinearSpace for B being Subset of V for I being affinely-independent Subset of V st B c= I & x in Affin B holds x |-- B = x |-- I let V be RealLinearSpace; ::_thesis: for B being Subset of V for I being affinely-independent Subset of V st B c= I & x in Affin B holds x |-- B = x |-- I let B be Subset of V; ::_thesis: for I being affinely-independent Subset of V st B c= I & x in Affin B holds x |-- B = x |-- I let I be affinely-independent Subset of V; ::_thesis: ( B c= I & x in Affin B implies x |-- B = x |-- I ) assume that A1: B c= I and A2: x in Affin B ; ::_thesis: x |-- B = x |-- I B is affinely-independent by A1, Th43; then A3: ( Sum (x |-- B) = x & sum (x |-- B) = 1 ) by A2, Def7; ( Affin B c= Affin I & x |-- B is Linear_Combination of I ) by A1, Th52, RLVECT_2:21; hence x |-- B = x |-- I by A2, A3, Def7; ::_thesis: verum end; theorem Th78: :: RLAFFIN1:78 for r, s being Real for V being RealLinearSpace for v1, v2 being VECTOR of V for A being Subset of V st v1 in Affin A & v2 in Affin A & r + s = 1 holds (r * v1) + (s * v2) in Affin A proof let r, s be Real; ::_thesis: for V being RealLinearSpace for v1, v2 being VECTOR of V for A being Subset of V st v1 in Affin A & v2 in Affin A & r + s = 1 holds (r * v1) + (s * v2) in Affin A let V be RealLinearSpace; ::_thesis: for v1, v2 being VECTOR of V for A being Subset of V st v1 in Affin A & v2 in Affin A & r + s = 1 holds (r * v1) + (s * v2) in Affin A let v1, v2 be VECTOR of V; ::_thesis: for A being Subset of V st v1 in Affin A & v2 in Affin A & r + s = 1 holds (r * v1) + (s * v2) in Affin A let A be Subset of V; ::_thesis: ( v1 in Affin A & v2 in Affin A & r + s = 1 implies (r * v1) + (s * v2) in Affin A ) A1: Affin A = { (Sum L) where L is Linear_Combination of A : sum L = 1 } by Th59; assume v1 in Affin A ; ::_thesis: ( not v2 in Affin A or not r + s = 1 or (r * v1) + (s * v2) in Affin A ) then consider L1 being Linear_Combination of A such that A2: v1 = Sum L1 and A3: sum L1 = 1 by A1; assume v2 in Affin A ; ::_thesis: ( not r + s = 1 or (r * v1) + (s * v2) in Affin A ) then consider L2 being Linear_Combination of A such that A4: v2 = Sum L2 and A5: sum L2 = 1 by A1; A6: Sum ((r * L1) + (s * L2)) = (Sum (r * L1)) + (Sum (s * L2)) by RLVECT_3:1 .= (r * (Sum L1)) + (Sum (s * L2)) by RLVECT_3:2 .= (r * v1) + (s * v2) by A2, A4, RLVECT_3:2 ; ( r * L1 is Linear_Combination of A & s * L2 is Linear_Combination of A ) by RLVECT_2:44; then A7: (r * L1) + (s * L2) is Linear_Combination of A by RLVECT_2:38; assume A8: r + s = 1 ; ::_thesis: (r * v1) + (s * v2) in Affin A sum ((r * L1) + (s * L2)) = (sum (r * L1)) + (sum (s * L2)) by Th34 .= (r * (sum L1)) + (sum (s * L2)) by Th35 .= (r * 1) + (s * 1) by A3, A5, Th35 .= 1 by A8 ; hence (r * v1) + (s * v2) in Affin A by A1, A7, A6; ::_thesis: verum end; theorem Th79: :: RLAFFIN1:79 for V being RealLinearSpace for A, B being finite Subset of V st A is affinely-independent & Affin A c= Affin B holds card A <= card B proof let V be RealLinearSpace; ::_thesis: for A, B being finite Subset of V st A is affinely-independent & Affin A c= Affin B holds card A <= card B let A, B be finite Subset of V; ::_thesis: ( A is affinely-independent & Affin A c= Affin B implies card A <= card B ) assume that A1: A is affinely-independent and A2: Affin A c= Affin B ; ::_thesis: card A <= card B percases ( A is empty or not A is empty ) ; suppose A is empty ; ::_thesis: card A <= card B hence card A <= card B ; ::_thesis: verum end; suppose not A is empty ; ::_thesis: card A <= card B then consider p being set such that A3: p in A by XBOOLE_0:def_1; reconsider p = p as Element of V by A3; A4: A c= Affin A by Lm7; then A5: p in Affin A by A3; set LA = Lin ((- p) + A); A6: card A = card ((- p) + A) by Th7; {} V c= B by XBOOLE_1:2; then consider Ib being affinely-independent Subset of V such that {} V c= Ib and A7: Ib c= B and A8: Affin Ib = Affin B by Th60; not Ib is empty by A2, A3, A8; then consider q being set such that A9: q in Ib by XBOOLE_0:def_1; reconsider q = q as Element of V by A9; set LI = Lin ((- q) + Ib); A10: card Ib = card ((- q) + Ib) by Th7; (- q) + Ib c= the carrier of (Lin ((- q) + Ib)) proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in (- q) + Ib or x in the carrier of (Lin ((- q) + Ib)) ) assume x in (- q) + Ib ; ::_thesis: x in the carrier of (Lin ((- q) + Ib)) then x in Lin ((- q) + Ib) by RLVECT_3:15; hence x in the carrier of (Lin ((- q) + Ib)) by STRUCT_0:def_5; ::_thesis: verum end; then reconsider qI = (- q) + Ib as finite Subset of (Lin ((- q) + Ib)) by A7, A10; (- q) + q = 0. V by RLVECT_1:5; then A11: 0. V in qI by A9; then A12: Lin ((- q) + Ib) = Lin ((((- q) + Ib) \ {(0. V)}) \/ {(0. V)}) by ZFMISC_1:116 .= Lin (((- q) + Ib) \ {(0. V)}) by Lm9 .= Lin (qI \ {(0. V)}) by RLVECT_5:20 ; A13: ((- q) + Ib) \ {(0. V)} is linearly-independent by A9, Th41; then qI \ {(0. V)} is linearly-independent by RLVECT_5:15; then qI \ {(0. V)} is Basis of Lin ((- q) + Ib) by A12, RLVECT_3:def_3; then reconsider LI = Lin ((- q) + Ib) as finite-dimensional Subspace of V by RLVECT_5:def_1; A14: Ib c= Affin Ib by Lm7; then A15: Affin Ib = q + (Up LI) by A9, Th57; A16: Affin A = p + (Up (Lin ((- p) + A))) by A3, A4, Th57; (- p) + A c= the carrier of LI proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in (- p) + A or x in the carrier of LI ) A17: 2 + (- 1) = 1 ; (2 * q) + ((- 1) * p) = ((1 + 1) * q) + ((- 1) * p) .= ((1 * q) + (1 * q)) + ((- 1) * p) by RLVECT_1:def_6 .= ((1 * q) + (1 * q)) + (- p) by RLVECT_1:16 .= ((1 * q) + q) + (- p) by RLVECT_1:def_8 .= (q + q) + (- p) by RLVECT_1:def_8 .= (q + q) - p by RLVECT_1:def_11 .= (q - p) + q by RLVECT_1:28 ; then ( q + (Up LI) = q + LI & (q - p) + q in q + (Up LI) ) by A2, A8, A5, A9, A14, A15, A17, Th78, RUSUB_4:30; then A18: q - p in LI by RLSUB_1:61; assume x in (- p) + A ; ::_thesis: x in the carrier of LI then A19: x in Lin ((- p) + A) by RLVECT_3:15; then x in V by RLSUB_1:9; then reconsider w = x as Element of V by STRUCT_0:def_5; w in Up (Lin ((- p) + A)) by A19, STRUCT_0:def_5; then p + w in Affin A by A16; then p + w in q + (Up LI) by A2, A8, A15; then consider u being Element of V such that A20: p + w = q + u and A21: u in Up LI ; A22: w = (q + u) - p by A20, RLVECT_4:1 .= q + (u - p) by RLVECT_1:28 .= u - (p - q) by RLVECT_1:29 .= u + (- (p - q)) by RLVECT_1:def_11 .= u + (q + (- p)) by RLVECT_1:33 .= u + (q - p) by RLVECT_1:def_11 ; u in LI by A21, STRUCT_0:def_5; then w in LI by A18, A22, RLSUB_1:20; hence x in the carrier of LI by STRUCT_0:def_5; ::_thesis: verum end; then reconsider LA = Lin ((- p) + A) as Subspace of LI by RLVECT_5:19; (- p) + A c= the carrier of LA proof let x be set ; :: according to TARSKI:def_3 ::_thesis: ( not x in (- p) + A or x in the carrier of LA ) assume x in (- p) + A ; ::_thesis: x in the carrier of LA then x in LA by RLVECT_3:15; hence x in the carrier of LA by STRUCT_0:def_5; ::_thesis: verum end; then reconsider pA = (- p) + A as finite Subset of LA by A6; (- p) + p = 0. V by RLVECT_1:5; then A23: 0. V in pA by A3; then A24: {(0. V)} c= pA by ZFMISC_1:31; A25: ((- p) + A) \ {(0. V)} is linearly-independent by A1, A3, Th41; A26: card {(0. V)} = 1 by CARD_1:30; A27: {(0. V)} c= qI by A11, ZFMISC_1:31; A28: dim LI = card (qI \ {(0. V)}) by A13, A12, RLVECT_5:15, RLVECT_5:29 .= (card qI) - 1 by A27, A26, CARD_2:44 ; Lin ((- p) + A) = Lin ((((- p) + A) \ {(0. V)}) \/ {(0. V)}) by A23, ZFMISC_1:116 .= Lin (((- p) + A) \ {(0. V)}) by Lm9 .= Lin (pA \ {(0. V)}) by RLVECT_5:20 ; then dim LA = card (pA \ {(0. V)}) by A25, RLVECT_5:15, RLVECT_5:29 .= (card A) - 1 by A6, A26, A24, CARD_2:44 ; then (card A) - 1 <= (card qI) - 1 by A28, RLVECT_5:28; then A29: card A <= card qI by XREAL_1:9; card qI <= card B by A7, A10, NAT_1:43; hence card A <= card B by A29, XXREAL_0:2; ::_thesis: verum end; end; end; theorem :: RLAFFIN1:80 for V being RealLinearSpace for A, B being finite Subset of V st A is affinely-independent & Affin A c= Affin B & card A = card B holds B is affinely-independent proof let V be RealLinearSpace; ::_thesis: for A, B being finite Subset of V st A is affinely-independent & Affin A c= Affin B & card A = card B holds B is affinely-independent let A, B be finite Subset of V; ::_thesis: ( A is affinely-independent & Affin A c= Affin B & card A = card B implies B is affinely-independent ) assume A1: ( A is affinely-independent & Affin A c= Affin B & card A = card B ) ; ::_thesis: B is affinely-independent {} V c= B by XBOOLE_1:2; then consider Ib being affinely-independent Subset of V such that {} V c= Ib and A2: Ib c= B and A3: Affin Ib = Affin B by Th60; reconsider IB = Ib as finite Subset of V by A2; A4: card IB <= card B by A3, Th79; card B <= card IB by A1, A3, Th79; hence B is affinely-independent by A2, A4, CARD_FIN:1, XXREAL_0:1; ::_thesis: verum end; theorem :: RLAFFIN1:81 for r, s being Real for V being RealLinearSpace for v being VECTOR of V for L1, L2 being Linear_Combination of V st L1 . v <> L2 . v holds ( ((r * L1) + ((1 - r) * L2)) . v = s iff r = ((L2 . v) - s) / ((L2 . v) - (L1 . v)) ) proof let r, s be Real; ::_thesis: for V being RealLinearSpace for v being VECTOR of V for L1, L2 being Linear_Combination of V st L1 . v <> L2 . v holds ( ((r * L1) + ((1 - r) * L2)) . v = s iff r = ((L2 . v) - s) / ((L2 . v) - (L1 . v)) ) let V be RealLinearSpace; ::_thesis: for v being VECTOR of V for L1, L2 being Linear_Combination of V st L1 . v <> L2 . v holds ( ((r * L1) + ((1 - r) * L2)) . v = s iff r = ((L2 . v) - s) / ((L2 . v) - (L1 . v)) ) let v be VECTOR of V; ::_thesis: for L1, L2 being Linear_Combination of V st L1 . v <> L2 . v holds ( ((r * L1) + ((1 - r) * L2)) . v = s iff r = ((L2 . v) - s) / ((L2 . v) - (L1 . v)) ) let L1, L2 be Linear_Combination of V; ::_thesis: ( L1 . v <> L2 . v implies ( ((r * L1) + ((1 - r) * L2)) . v = s iff r = ((L2 . v) - s) / ((L2 . v) - (L1 . v)) ) ) set u1 = L1 . v; set u2 = L2 . v; A1: ((r * L1) + ((1 - r) * L2)) . v = ((r * L1) . v) + (((1 - r) * L2) . v) by RLVECT_2:def_10 .= (r * (L1 . v)) + (((1 - r) * L2) . v) by RLVECT_2:def_11 .= (r * (L1 . v)) + (((- r) + 1) * (L2 . v)) by RLVECT_2:def_11 .= (r * ((L1 . v) - (L2 . v))) + (L2 . v) ; assume A2: L1 . v <> L2 . v ; ::_thesis: ( ((r * L1) + ((1 - r) * L2)) . v = s iff r = ((L2 . v) - s) / ((L2 . v) - (L1 . v)) ) then A3: (L1 . v) - (L2 . v) <> 0 ; A4: (L2 . v) - (L1 . v) <> 0 by A2; hereby ::_thesis: ( r = ((L2 . v) - s) / ((L2 . v) - (L1 . v)) implies ((r * L1) + ((1 - r) * L2)) . v = s ) assume ((r * L1) + ((1 - r) * L2)) . v = s ; ::_thesis: r = ((L2 . v) - s) / ((L2 . v) - (L1 . v)) then r * ((L2 . v) - (L1 . v)) = ((L2 . v) - s) * 1 by A1; then r / 1 = ((L2 . v) - s) / ((L2 . v) - (L1 . v)) by A4, XCMPLX_1:94; hence r = ((L2 . v) - s) / ((L2 . v) - (L1 . v)) ; ::_thesis: verum end; assume r = ((L2 . v) - s) / ((L2 . v) - (L1 . v)) ; ::_thesis: ((r * L1) + ((1 - r) * L2)) . v = s hence ((r * L1) + ((1 - r) * L2)) . v = ((((L2 . v) - s) / (- ((L1 . v) - (L2 . v)))) * ((L1 . v) - (L2 . v))) + (L2 . v) by A1 .= (((- ((L2 . v) - s)) / ((L1 . v) - (L2 . v))) * ((L1 . v) - (L2 . v))) + (L2 . v) by XCMPLX_1:192 .= (- ((L2 . v) - s)) + (L2 . v) by A3, XCMPLX_1:87 .= s ; ::_thesis: verum end; theorem :: RLAFFIN1:82 for V being RealLinearSpace for v being VECTOR of V for A being Subset of V holds ( A \/ {v} is affinely-independent iff ( A is affinely-independent & ( v in A or not v in Affin A ) ) ) proof let V be RealLinearSpace; ::_thesis: for v being VECTOR of V for A being Subset of V holds ( A \/ {v} is affinely-independent iff ( A is affinely-independent & ( v in A or not v in Affin A ) ) ) let v be VECTOR of V; ::_thesis: for A being Subset of V holds ( A \/ {v} is affinely-independent iff ( A is affinely-independent & ( v in A or not v in Affin A ) ) ) let A be Subset of V; ::_thesis: ( A \/ {v} is affinely-independent iff ( A is affinely-independent & ( v in A or not v in Affin A ) ) ) set Av = A \/ {v}; v in {v} by TARSKI:def_1; then A1: v in A \/ {v} by XBOOLE_0:def_3; A2: A c= A \/ {v} by XBOOLE_1:7; hereby ::_thesis: ( A is affinely-independent & ( v in A or not v in Affin A ) implies A \/ {v} is affinely-independent ) assume A3: A \/ {v} is affinely-independent ; ::_thesis: ( A is affinely-independent & ( v in A or not v in Affin A ) ) hence A is affinely-independent by Th43, XBOOLE_1:7; ::_thesis: ( v in A or not v in Affin A ) ( v in Affin A implies v in A ) proof assume v in Affin A ; ::_thesis: v in A then {v} c= Affin A by ZFMISC_1:31; then Affin (A \/ {v}) = Affin A by Th69; hence v in A by A2, A1, A3, Th58; ::_thesis: verum end; hence ( v in A or not v in Affin A ) ; ::_thesis: verum end; assume that A4: A is affinely-independent and A5: ( v in A or not v in Affin A ) ; ::_thesis: A \/ {v} is affinely-independent percases ( v in A or ( not v in Affin A & not v in A ) ) by A5; suppose v in A ; ::_thesis: A \/ {v} is affinely-independent hence A \/ {v} is affinely-independent by A4, ZFMISC_1:40; ::_thesis: verum end; supposeA6: ( not v in Affin A & not v in A ) ; ::_thesis: A \/ {v} is affinely-independent consider I being affinely-independent Subset of V such that A7: A c= I and A8: I c= A \/ {v} and A9: Affin I = Affin (A \/ {v}) by A2, A4, Th60; assume A10: not A \/ {v} is affinely-independent ; ::_thesis: contradiction not v in I proof assume v in I ; ::_thesis: contradiction then {v} c= I by ZFMISC_1:31; hence contradiction by A7, A10, Th43, XBOOLE_1:8; ::_thesis: verum end; then A11: I c= (A \/ {v}) \ {v} by A8, ZFMISC_1:34; A12: A \/ {v} c= Affin (A \/ {v}) by Lm7; (A \/ {v}) \ {v} = A by A6, ZFMISC_1:117; then I = A by A7, A11, XBOOLE_0:def_10; hence contradiction by A1, A6, A9, A12; ::_thesis: verum end; end; end; theorem :: RLAFFIN1:83 for r, s being Real for V being RealLinearSpace for w, v1, v2 being VECTOR of V for A being Subset of V st not w in Affin A & v1 in A & v2 in A & r <> 1 & (r * w) + ((1 - r) * v1) = (s * w) + ((1 - s) * v2) holds ( r = s & v1 = v2 ) proof let r, s be Real; ::_thesis: for V being RealLinearSpace for w, v1, v2 being VECTOR of V for A being Subset of V st not w in Affin A & v1 in A & v2 in A & r <> 1 & (r * w) + ((1 - r) * v1) = (s * w) + ((1 - s) * v2) holds ( r = s & v1 = v2 ) let V be RealLinearSpace; ::_thesis: for w, v1, v2 being VECTOR of V for A being Subset of V st not w in Affin A & v1 in A & v2 in A & r <> 1 & (r * w) + ((1 - r) * v1) = (s * w) + ((1 - s) * v2) holds ( r = s & v1 = v2 ) let w, v1, v2 be VECTOR of V; ::_thesis: for A being Subset of V st not w in Affin A & v1 in A & v2 in A & r <> 1 & (r * w) + ((1 - r) * v1) = (s * w) + ((1 - s) * v2) holds ( r = s & v1 = v2 ) let A be Subset of V; ::_thesis: ( not w in Affin A & v1 in A & v2 in A & r <> 1 & (r * w) + ((1 - r) * v1) = (s * w) + ((1 - s) * v2) implies ( r = s & v1 = v2 ) ) assume that A1: ( not w in Affin A & v1 in A & v2 in A ) and A2: r <> 1 and A3: (r * w) + ((1 - r) * v1) = (s * w) + ((1 - s) * v2) ; ::_thesis: ( r = s & v1 = v2 ) r * w = (r * w) + (0. V) by RLVECT_1:4 .= (r * w) + (((1 - r) * v1) - ((1 - r) * v1)) by RLVECT_1:15 .= ((s * w) + ((1 - s) * v2)) - ((1 - r) * v1) by A3, RLVECT_1:28 .= (((1 - s) * v2) - ((1 - r) * v1)) + (s * w) by RLVECT_1:28 ; then (r * w) - (s * w) = ((1 - s) * v2) - ((1 - r) * v1) by RLVECT_4:1; then A4: (r - s) * w = ((1 - s) * v2) - ((1 - r) * v1) by RLVECT_1:35; A5: A c= Affin A by Lm7; percases ( r <> s or r = s ) ; suppose r <> s ; ::_thesis: ( r = s & v1 = v2 ) then A6: r - s <> 0 ; A7: (1 / (r - s)) * (1 - s) = ((r - s) - (r - 1)) / (r - s) by XCMPLX_1:99 .= ((r - s) / (r - s)) - ((r - 1) / (r - s)) by XCMPLX_1:120 .= 1 - ((r - 1) / (r - s)) by A6, XCMPLX_1:60 ; A8: - ((1 / (r - s)) * (1 - r)) = - ((1 - r) / (r - s)) by XCMPLX_1:99 .= (- (1 - r)) / (r - s) by XCMPLX_1:187 ; 1 = (r - s) * (1 / (r - s)) by A6, XCMPLX_1:106; then w = ((1 / (r - s)) * (r - s)) * w by RLVECT_1:def_8 .= (1 / (r - s)) * ((r - s) * w) by RLVECT_1:def_7 .= ((1 / (r - s)) * ((1 - s) * v2)) - ((1 / (r - s)) * ((1 - r) * v1)) by A4, RLVECT_1:34 .= (((1 / (r - s)) * (1 - s)) * v2) - ((1 / (r - s)) * ((1 - r) * v1)) by RLVECT_1:def_7 .= (((1 / (r - s)) * (1 - s)) * v2) - (((1 / (r - s)) * (1 - r)) * v1) by RLVECT_1:def_7 .= (((1 / (r - s)) * (1 - s)) * v2) + (- (((1 / (r - s)) * (1 - r)) * v1)) by RLVECT_1:def_11 .= ((1 - ((r - 1) / (r - s))) * v2) + (((r - 1) / (r - s)) * v1) by A7, A8, RLVECT_4:3 ; hence ( r = s & v1 = v2 ) by A1, A5, RUSUB_4:def_4; ::_thesis: verum end; supposeA9: r = s ; ::_thesis: ( r = s & v1 = v2 ) A10: 1 - r <> 0 by A2; (1 - r) * v1 = (1 - r) * v2 by A3, A9, RLVECT_1:8; hence ( r = s & v1 = v2 ) by A9, A10, RLVECT_1:36; ::_thesis: verum end; end; end; theorem :: RLAFFIN1:84 for r being Real for V being RealLinearSpace for v, w, p being VECTOR of V for I being affinely-independent Subset of V st v in I & w in Affin I & p in Affin (I \ {v}) & w = (r * v) + ((1 - r) * p) holds r = (w |-- I) . v proof let r be Real; ::_thesis: for V being RealLinearSpace for v, w, p being VECTOR of V for I being affinely-independent Subset of V st v in I & w in Affin I & p in Affin (I \ {v}) & w = (r * v) + ((1 - r) * p) holds r = (w |-- I) . v let V be RealLinearSpace; ::_thesis: for v, w, p being VECTOR of V for I being affinely-independent Subset of V st v in I & w in Affin I & p in Affin (I \ {v}) & w = (r * v) + ((1 - r) * p) holds r = (w |-- I) . v let v, w, p be VECTOR of V; ::_thesis: for I being affinely-independent Subset of V st v in I & w in Affin I & p in Affin (I \ {v}) & w = (r * v) + ((1 - r) * p) holds r = (w |-- I) . v let I be affinely-independent Subset of V; ::_thesis: ( v in I & w in Affin I & p in Affin (I \ {v}) & w = (r * v) + ((1 - r) * p) implies r = (w |-- I) . v ) assume that A1: v in I and w in Affin I and A2: p in Affin (I \ {v}) and A3: w = (r * v) + ((1 - r) * p) ; ::_thesis: r = (w |-- I) . v A4: I c= conv I by CONVEX1:41; Carrier (p |-- (I \ {v})) c= I \ {v} by RLVECT_2:def_6; then not v in Carrier (p |-- (I \ {v})) by ZFMISC_1:56; then A5: (p |-- (I \ {v})) . v = 0 ; I \ {v} c= I by XBOOLE_1:36; then ( Affin (I \ {v}) c= Affin I & I c= Affin I ) by Lm7, Th52; hence (w |-- I) . v = (((1 - r) * (p |-- I)) + (r * (v |-- I))) . v by A1, A2, A3, Th70 .= (((1 - r) * (p |-- I)) . v) + ((r * (v |-- I)) . v) by RLVECT_2:def_10 .= (((1 - r) * (p |-- I)) . v) + (r * ((v |-- I) . v)) by RLVECT_2:def_11 .= ((1 - r) * ((p |-- I) . v)) + (r * ((v |-- I) . v)) by RLVECT_2:def_11 .= ((1 - r) * ((p |-- I) . v)) + (r * 1) by A1, A4, Th72 .= ((1 - r) * ((p |-- (I \ {v})) . v)) + (r * 1) by A2, Th77, XBOOLE_1:36 .= r by A5 ; ::_thesis: verum end;