:: PAPDESAF semantic presentation begin registration let OAS be OAffinSpace; cluster Lambda OAS -> non trivial AffinSpace-like ; correctness coherence ( Lambda OAS is AffinSpace-like & not Lambda OAS is trivial ); by DIRAF:41; end; registration let OAS be OAffinPlane; cluster Lambda OAS -> 2-dimensional ; correctness coherence Lambda OAS is 2-dimensional ; by DIRAF:45; end; theorem Th1: :: PAPDESAF:1 for OAS being OAffinSpace for x being set holds ( ( x is Element of OAS implies x is Element of (Lambda OAS) ) & ( x is Element of (Lambda OAS) implies x is Element of OAS ) & ( x is Subset of OAS implies x is Subset of (Lambda OAS) ) & ( x is Subset of (Lambda OAS) implies x is Subset of OAS ) ) proof let OAS be OAffinSpace; ::_thesis: for x being set holds ( ( x is Element of OAS implies x is Element of (Lambda OAS) ) & ( x is Element of (Lambda OAS) implies x is Element of OAS ) & ( x is Subset of OAS implies x is Subset of (Lambda OAS) ) & ( x is Subset of (Lambda OAS) implies x is Subset of OAS ) ) Lambda OAS = AffinStruct(# the carrier of OAS,(lambda the CONGR of OAS) #) by DIRAF:def_2; hence for x being set holds ( ( x is Element of OAS implies x is Element of (Lambda OAS) ) & ( x is Element of (Lambda OAS) implies x is Element of OAS ) & ( x is Subset of OAS implies x is Subset of (Lambda OAS) ) & ( x is Subset of (Lambda OAS) implies x is Subset of OAS ) ) ; ::_thesis: verum end; theorem Th2: :: PAPDESAF:2 for OAS being OAffinSpace for a, b, c being Element of OAS for a9, b9, c9 being Element of (Lambda OAS) st a = a9 & b = b9 & c = c9 holds ( LIN a,b,c iff LIN a9,b9,c9 ) proof let OAS be OAffinSpace; ::_thesis: for a, b, c being Element of OAS for a9, b9, c9 being Element of (Lambda OAS) st a = a9 & b = b9 & c = c9 holds ( LIN a,b,c iff LIN a9,b9,c9 ) let a, b, c be Element of OAS; ::_thesis: for a9, b9, c9 being Element of (Lambda OAS) st a = a9 & b = b9 & c = c9 holds ( LIN a,b,c iff LIN a9,b9,c9 ) let a9, b9, c9 be Element of (Lambda OAS); ::_thesis: ( a = a9 & b = b9 & c = c9 implies ( LIN a,b,c iff LIN a9,b9,c9 ) ) assume A1: ( a = a9 & b = b9 & c = c9 ) ; ::_thesis: ( LIN a,b,c iff LIN a9,b9,c9 ) A2: now__::_thesis:_(_LIN_a,b,c_implies_LIN_a9,b9,c9_) assume LIN a,b,c ; ::_thesis: LIN a9,b9,c9 then a,b '||' a,c by DIRAF:def_5; then a9,b9 // a9,c9 by A1, DIRAF:38; hence LIN a9,b9,c9 by AFF_1:def_1; ::_thesis: verum end; now__::_thesis:_(_LIN_a9,b9,c9_implies_LIN_a,b,c_) assume LIN a9,b9,c9 ; ::_thesis: LIN a,b,c then a9,b9 // a9,c9 by AFF_1:def_1; then a,b '||' a,c by A1, DIRAF:38; hence LIN a,b,c by DIRAF:def_5; ::_thesis: verum end; hence ( LIN a,b,c iff LIN a9,b9,c9 ) by A2; ::_thesis: verum end; theorem Th3: :: PAPDESAF:3 for V being RealLinearSpace for x being set holds ( x is Element of (OASpace V) iff x is VECTOR of V ) proof let V be RealLinearSpace; ::_thesis: for x being set holds ( x is Element of (OASpace V) iff x is VECTOR of V ) let x be set ; ::_thesis: ( x is Element of (OASpace V) iff x is VECTOR of V ) OASpace V = AffinStruct(# the carrier of V,(DirPar V) #) by ANALOAF:def_4; hence ( x is Element of (OASpace V) iff x is VECTOR of V ) ; ::_thesis: verum end; theorem Th4: :: PAPDESAF:4 for V being RealLinearSpace for OAS being OAffinSpace st OAS = OASpace V holds for a, b, c, d being Element of OAS for u, v, w, y being VECTOR of V st a = u & b = v & c = w & d = y holds ( a,b '||' c,d iff u,v '||' w,y ) proof let V be RealLinearSpace; ::_thesis: for OAS being OAffinSpace st OAS = OASpace V holds for a, b, c, d being Element of OAS for u, v, w, y being VECTOR of V st a = u & b = v & c = w & d = y holds ( a,b '||' c,d iff u,v '||' w,y ) let OAS be OAffinSpace; ::_thesis: ( OAS = OASpace V implies for a, b, c, d being Element of OAS for u, v, w, y being VECTOR of V st a = u & b = v & c = w & d = y holds ( a,b '||' c,d iff u,v '||' w,y ) ) assume A1: OAS = OASpace V ; ::_thesis: for a, b, c, d being Element of OAS for u, v, w, y being VECTOR of V st a = u & b = v & c = w & d = y holds ( a,b '||' c,d iff u,v '||' w,y ) let a, b, c, d be Element of OAS; ::_thesis: for u, v, w, y being VECTOR of V st a = u & b = v & c = w & d = y holds ( a,b '||' c,d iff u,v '||' w,y ) let u, v, w, y be VECTOR of V; ::_thesis: ( a = u & b = v & c = w & d = y implies ( a,b '||' c,d iff u,v '||' w,y ) ) assume A2: ( a = u & b = v & c = w & d = y ) ; ::_thesis: ( a,b '||' c,d iff u,v '||' w,y ) A3: now__::_thesis:_(_u,v_'||'_w,y_implies_a,b_'||'_c,d_) assume u,v '||' w,y ; ::_thesis: a,b '||' c,d then ( u,v // w,y or u,v // y,w ) by GEOMTRAP:def_1; then ( a,b // c,d or a,b // d,c ) by A1, A2, GEOMTRAP:2; hence a,b '||' c,d by DIRAF:def_4; ::_thesis: verum end; now__::_thesis:_(_a,b_'||'_c,d_implies_u,v_'||'_w,y_) assume a,b '||' c,d ; ::_thesis: u,v '||' w,y then ( a,b // c,d or a,b // d,c ) by DIRAF:def_4; then ( u,v // w,y or u,v // y,w ) by A1, A2, GEOMTRAP:2; hence u,v '||' w,y by GEOMTRAP:def_1; ::_thesis: verum end; hence ( a,b '||' c,d iff u,v '||' w,y ) by A3; ::_thesis: verum end; theorem :: PAPDESAF:5 for V being RealLinearSpace for OAS being OAffinSpace st OAS = OASpace V holds ex u, v being VECTOR of V st for a, b being Real st (a * u) + (b * v) = 0. V holds ( a = 0 & b = 0 ) proof let V be RealLinearSpace; ::_thesis: for OAS being OAffinSpace st OAS = OASpace V holds ex u, v being VECTOR of V st for a, b being Real st (a * u) + (b * v) = 0. V holds ( a = 0 & b = 0 ) let OAS be OAffinSpace; ::_thesis: ( OAS = OASpace V implies ex u, v being VECTOR of V st for a, b being Real st (a * u) + (b * v) = 0. V holds ( a = 0 & b = 0 ) ) assume A1: OAS = OASpace V ; ::_thesis: ex u, v being VECTOR of V st for a, b being Real st (a * u) + (b * v) = 0. V holds ( a = 0 & b = 0 ) consider a, b, c, d being Element of OAS such that A2: ( not a,b // c,d & not a,b // d,c ) by ANALOAF:def_5; reconsider u = a, v = b, w = c, y = d as VECTOR of V by A1, Th3; take z1 = v - u; ::_thesis: ex v being VECTOR of V st for a, b being Real st (a * z1) + (b * v) = 0. V holds ( a = 0 & b = 0 ) take z2 = y - w; ::_thesis: for a, b being Real st (a * z1) + (b * z2) = 0. V holds ( a = 0 & b = 0 ) now__::_thesis:_for_r1,_r2_being_Real_st_(r1_*_z1)_+_(r2_*_z2)_=_0._V_&_(_r1_<>_0_or_r2_<>_0_)_holds_ (_r1_=_0_&_r2_=_0_) let r1, r2 be Real; ::_thesis: ( (r1 * z1) + (r2 * z2) = 0. V & ( r1 <> 0 or r2 <> 0 ) implies ( r1 = 0 & r2 = 0 ) ) assume (r1 * z1) + (r2 * z2) = 0. V ; ::_thesis: ( ( r1 <> 0 or r2 <> 0 ) implies ( r1 = 0 & r2 = 0 ) ) then A3: r1 * z1 = - (r2 * z2) by RLVECT_1:6 .= r2 * (- z2) by RLVECT_1:25 .= (- r2) * z2 by RLVECT_1:24 ; assume ( r1 <> 0 or r2 <> 0 ) ; ::_thesis: ( r1 = 0 & r2 = 0 ) then ( r1 <> 0 or - r2 <> 0 ) ; then ( u,v // w,y or u,v // y,w ) by A3, ANALMETR:14; hence ( r1 = 0 & r2 = 0 ) by A1, A2, GEOMTRAP:2; ::_thesis: verum end; hence for a, b being Real st (a * z1) + (b * z2) = 0. V holds ( a = 0 & b = 0 ) ; ::_thesis: verum end; definition let AS be AffinSpace; redefine attr AS is Fanoian means :Def1: :: PAPDESAF:def 1 for a, b, c, d being Element of AS st a,b // c,d & a,c // b,d & a,d // b,c holds a,b // a,c; compatibility ( AS is Fanoian iff for a, b, c, d being Element of AS st a,b // c,d & a,c // b,d & a,d // b,c holds a,b // a,c ) proof thus ( AS is Fanoian implies for a, b, c, d being Element of AS st a,b // c,d & a,c // b,d & a,d // b,c holds a,b // a,c ) ::_thesis: ( ( for a, b, c, d being Element of AS st a,b // c,d & a,c // b,d & a,d // b,c holds a,b // a,c ) implies AS is Fanoian ) proof assume A1: for a, b, c, d being Element of AS st a,b // c,d & a,c // b,d & a,d // b,c holds LIN a,b,c ; :: according to TRANSLAC:def_1 ::_thesis: for a, b, c, d being Element of AS st a,b // c,d & a,c // b,d & a,d // b,c holds a,b // a,c let a, b, c, d be Element of AS; ::_thesis: ( a,b // c,d & a,c // b,d & a,d // b,c implies a,b // a,c ) assume ( a,b // c,d & a,c // b,d & a,d // b,c ) ; ::_thesis: a,b // a,c then LIN a,b,c by A1; hence a,b // a,c by AFF_1:def_1; ::_thesis: verum end; assume A2: for a, b, c, d being Element of AS st a,b // c,d & a,c // b,d & a,d // b,c holds a,b // a,c ; ::_thesis: AS is Fanoian let a, b, c, d be Element of AS; :: according to TRANSLAC:def_1 ::_thesis: ( not a,b // c,d or not a,c // b,d or not a,d // b,c or LIN a,b,c ) assume ( a,b // c,d & a,c // b,d & a,d // b,c ) ; ::_thesis: LIN a,b,c then a,b // a,c by A2; hence LIN a,b,c by AFF_1:def_1; ::_thesis: verum end; end; :: deftheorem Def1 defines Fanoian PAPDESAF:def_1_:_ for AS being AffinSpace holds ( AS is Fanoian iff for a, b, c, d being Element of AS st a,b // c,d & a,c // b,d & a,d // b,c holds a,b // a,c ); definition let IT be OAffinSpace; attrIT is Pappian means :Def2: :: PAPDESAF:def 2 Lambda IT is Pappian ; attrIT is Desarguesian means :Def3: :: PAPDESAF:def 3 Lambda IT is Desarguesian ; attrIT is Moufangian means :Def4: :: PAPDESAF:def 4 Lambda IT is Moufangian ; attrIT is translation means :Def5: :: PAPDESAF:def 5 Lambda IT is translational ; end; :: deftheorem Def2 defines Pappian PAPDESAF:def_2_:_ for IT being OAffinSpace holds ( IT is Pappian iff Lambda IT is Pappian ); :: deftheorem Def3 defines Desarguesian PAPDESAF:def_3_:_ for IT being OAffinSpace holds ( IT is Desarguesian iff Lambda IT is Desarguesian ); :: deftheorem Def4 defines Moufangian PAPDESAF:def_4_:_ for IT being OAffinSpace holds ( IT is Moufangian iff Lambda IT is Moufangian ); :: deftheorem Def5 defines translation PAPDESAF:def_5_:_ for IT being OAffinSpace holds ( IT is translation iff Lambda IT is translational ); definition let OAS be OAffinSpace; attrOAS is satisfying_DES means :Def6: :: PAPDESAF:def 6 for o, a, b, c, a1, b1, c1 being Element of OAS st o,a // o,a1 & o,b // o,b1 & o,c // o,c1 & not LIN o,a,b & not LIN o,a,c & a,b // a1,b1 & a,c // a1,c1 holds b,c // b1,c1; end; :: deftheorem Def6 defines satisfying_DES PAPDESAF:def_6_:_ for OAS being OAffinSpace holds ( OAS is satisfying_DES iff for o, a, b, c, a1, b1, c1 being Element of OAS st o,a // o,a1 & o,b // o,b1 & o,c // o,c1 & not LIN o,a,b & not LIN o,a,c & a,b // a1,b1 & a,c // a1,c1 holds b,c // b1,c1 ); definition let OAS be OAffinSpace; attrOAS is satisfying_DES_1 means :Def7: :: PAPDESAF:def 7 for o, a, b, c, a1, b1, c1 being Element of OAS st a,o // o,a1 & b,o // o,b1 & c,o // o,c1 & not LIN o,a,b & not LIN o,a,c & a,b // b1,a1 & a,c // c1,a1 holds b,c // c1,b1; end; :: deftheorem Def7 defines satisfying_DES_1 PAPDESAF:def_7_:_ for OAS being OAffinSpace holds ( OAS is satisfying_DES_1 iff for o, a, b, c, a1, b1, c1 being Element of OAS st a,o // o,a1 & b,o // o,b1 & c,o // o,c1 & not LIN o,a,b & not LIN o,a,c & a,b // b1,a1 & a,c // c1,a1 holds b,c // c1,b1 ); theorem Th6: :: PAPDESAF:6 for OAS being OAffinSpace st OAS is satisfying_DES_1 holds OAS is satisfying_DES proof let OAS be OAffinSpace; ::_thesis: ( OAS is satisfying_DES_1 implies OAS is satisfying_DES ) assume A1: OAS is satisfying_DES_1 ; ::_thesis: OAS is satisfying_DES for o, a, b, c, a1, b1, c1 being Element of OAS st o,a // o,a1 & o,b // o,b1 & o,c // o,c1 & not LIN o,a,b & not LIN o,a,c & a,b // a1,b1 & a,c // a1,c1 holds b,c // b1,c1 proof let o, a, b, c, a1, b1, c1 be Element of OAS; ::_thesis: ( o,a // o,a1 & o,b // o,b1 & o,c // o,c1 & not LIN o,a,b & not LIN o,a,c & a,b // a1,b1 & a,c // a1,c1 implies b,c // b1,c1 ) assume that A2: o,a // o,a1 and A3: o,b // o,b1 and A4: o,c // o,c1 and A5: not LIN o,a,b and A6: not LIN o,a,c and A7: a,b // a1,b1 and A8: a,c // a1,c1 ; ::_thesis: b,c // b1,c1 consider a2 being Element of OAS such that A9: Mid a,o,a2 and A10: o <> a2 by DIRAF:13; A11: a,o // o,a2 by A9, DIRAF:def_3; A12: o <> a by A5, DIRAF:31; then consider c2 being Element of OAS such that A13: c,o // o,c2 and A14: c,a // a2,c2 by A11, ANALOAF:def_5; A15: c2,a2 // a,c by A14, DIRAF:2; A16: c2,o // o,c by A13, DIRAF:2; then Mid c2,o,c by DIRAF:def_3; then A17: LIN c2,o,c by DIRAF:28; LIN a,o,a2 by A9, DIRAF:28; then A18: LIN o,a2,a by DIRAF:30; A19: o <> c2 proof assume o = c2 ; ::_thesis: contradiction then o,a2 // a,c by A14, DIRAF:2; then o,a2 '||' a,c by DIRAF:def_4; then ( LIN o,a2,o & LIN o,a2,c ) by A10, A18, DIRAF:31, DIRAF:33; hence contradiction by A6, A10, A18, DIRAF:32; ::_thesis: verum end; A20: not LIN o,a2,c2 proof A21: LIN c2,o,o by DIRAF:31; A22: LIN o,a2,o by DIRAF:31; assume LIN o,a2,c2 ; ::_thesis: contradiction then LIN c2,o,a by A10, A18, A22, DIRAF:32; hence contradiction by A6, A17, A19, A21, DIRAF:32; ::_thesis: verum end; consider b2 being Element of OAS such that A23: b,o // o,b2 and A24: b,a // a2,b2 by A12, A11, ANALOAF:def_5; A25: b2,a2 // a,b by A24, DIRAF:2; a <> b by A5, DIRAF:31; then b2,a2 // a1,b1 by A7, A25, DIRAF:3; then A26: a2,b2 // b1,a1 by DIRAF:2; o <> c by A6, DIRAF:31; then A27: c2,o // o,c1 by A4, A16, DIRAF:3; A28: a,c // c2,a2 by A14, ANALOAF:def_5; A29: b2,o // o,b by A23, DIRAF:2; then Mid b2,o,b by DIRAF:def_3; then A30: LIN b2,o,b by DIRAF:28; A31: o <> b2 proof assume o = b2 ; ::_thesis: contradiction then o,a2 // a,b by A24, DIRAF:2; then o,a2 '||' a,b by DIRAF:def_4; then ( LIN o,a2,o & LIN o,a2,b ) by A10, A18, DIRAF:31, DIRAF:33; hence contradiction by A5, A10, A18, DIRAF:32; ::_thesis: verum end; A32: not LIN o,a2,b2 proof A33: LIN b2,o,o by DIRAF:31; A34: LIN o,a2,o by DIRAF:31; assume LIN o,a2,b2 ; ::_thesis: contradiction then LIN b2,o,a by A10, A18, A34, DIRAF:32; hence contradiction by A5, A30, A31, A33, DIRAF:32; ::_thesis: verum end; A35: now__::_thesis:_(_c2_=_b2_implies_b,c_//_b1,c1_) b2,a2 // a,b by A24, DIRAF:2; then A36: b2,a2 '||' a,b by DIRAF:def_4; assume A37: c2 = b2 ; ::_thesis: b,c // b1,c1 then A38: LIN o,b2,c by A17, DIRAF:30; c2,a2 // a,c by A14, DIRAF:2; then A39: b2,a2 '||' a,c by A37, DIRAF:def_4; ( not LIN o,b2,a2 & LIN o,b2,b ) by A30, A32, DIRAF:30; then b = c by A18, A38, A36, A39, PASCH:4; hence b,c // b1,c1 by DIRAF:4; ::_thesis: verum end; a2,o // o,a by A11, DIRAF:2; then A40: a2,o // o,a1 by A2, A12, DIRAF:3; a <> c by A6, DIRAF:31; then c2,a2 // a1,c1 by A8, A15, DIRAF:3; then A41: a2,c2 // c1,a1 by DIRAF:2; o <> b by A5, DIRAF:31; then b2,o // o,b1 by A3, A29, DIRAF:3; then A42: c2,b2 // b1,c1 by A1, A40, A27, A41, A26, A32, A20, Def7; a,b // b2,a2 by A24, ANALOAF:def_5; then b,c // c2,b2 by A1, A5, A6, A11, A23, A13, A28, Def7; hence b,c // b1,c1 by A42, A35, DIRAF:3; ::_thesis: verum end; hence OAS is satisfying_DES by Def6; ::_thesis: verum end; theorem Th7: :: PAPDESAF:7 for OAS being OAffinSpace for o, a, b, a9, b9 being Element of OAS st not LIN o,a,b & a,o // o,a9 & LIN o,b,b9 & a,b '||' a9,b9 holds ( b,o // o,b9 & a,b // b9,a9 ) proof let OAS be OAffinSpace; ::_thesis: for o, a, b, a9, b9 being Element of OAS st not LIN o,a,b & a,o // o,a9 & LIN o,b,b9 & a,b '||' a9,b9 holds ( b,o // o,b9 & a,b // b9,a9 ) let o, a, b, a9, b9 be Element of OAS; ::_thesis: ( not LIN o,a,b & a,o // o,a9 & LIN o,b,b9 & a,b '||' a9,b9 implies ( b,o // o,b9 & a,b // b9,a9 ) ) assume that A1: not LIN o,a,b and A2: a,o // o,a9 and A3: LIN o,b,b9 and A4: a,b '||' a9,b9 ; ::_thesis: ( b,o // o,b9 & a,b // b9,a9 ) ( Mid a,o,a9 & a,b '||' b9,a9 ) by A2, A4, DIRAF:22, DIRAF:def_3; then Mid b,o,b9 by A1, A3, PASCH:6; hence b,o // o,b9 by DIRAF:def_3; ::_thesis: a,b // b9,a9 hence a,b // b9,a9 by A1, A2, A4, PASCH:12; ::_thesis: verum end; theorem Th8: :: PAPDESAF:8 for OAS being OAffinSpace for o, a, b, a9, b9 being Element of OAS st not LIN o,a,b & o,a // o,a9 & LIN o,b,b9 & a,b '||' a9,b9 holds ( o,b // o,b9 & a,b // a9,b9 ) proof let OAS be OAffinSpace; ::_thesis: for o, a, b, a9, b9 being Element of OAS st not LIN o,a,b & o,a // o,a9 & LIN o,b,b9 & a,b '||' a9,b9 holds ( o,b // o,b9 & a,b // a9,b9 ) let o, a, b, a9, b9 be Element of OAS; ::_thesis: ( not LIN o,a,b & o,a // o,a9 & LIN o,b,b9 & a,b '||' a9,b9 implies ( o,b // o,b9 & a,b // a9,b9 ) ) assume that A1: not LIN o,a,b and A2: o,a // o,a9 and A3: LIN o,b,b9 and A4: a,b '||' a9,b9 ; ::_thesis: ( o,b // o,b9 & a,b // a9,b9 ) A5: o <> a by A1, DIRAF:31; consider a2 being Element of OAS such that A6: Mid a,o,a2 and A7: o <> a2 by DIRAF:13; a,o // o,a2 by A6, DIRAF:def_3; then consider b2 being Element of OAS such that A8: b,o // o,b2 and A9: b,a // a2,b2 by A5, ANALOAF:def_5; A10: o,b // b2,o by A8, DIRAF:2; a,o // o,a2 by A6, DIRAF:def_3; then a2,o // o,a by DIRAF:2; then A11: a2,o // o,a9 by A2, A5, DIRAF:3; LIN a,o,a2 by A6, DIRAF:28; then A12: LIN o,a2,a by DIRAF:30; A13: o <> b2 proof assume o = b2 ; ::_thesis: contradiction then o,a2 // a,b by A9, DIRAF:2; then o,a2 '||' a,b by DIRAF:def_4; then ( LIN o,a2,o & LIN o,a2,b ) by A7, A12, DIRAF:31, DIRAF:33; hence contradiction by A1, A7, A12, DIRAF:32; ::_thesis: verum end; Mid b,o,b2 by A8, DIRAF:def_3; then LIN b,o,b2 by DIRAF:28; then A14: LIN b2,o,b by DIRAF:30; A15: not LIN o,a2,b2 proof A16: LIN b2,o,o by DIRAF:31; A17: LIN o,a2,o by DIRAF:31; assume LIN o,a2,b2 ; ::_thesis: contradiction then LIN b2,o,a by A7, A12, A17, DIRAF:32; hence contradiction by A1, A14, A13, A16, DIRAF:32; ::_thesis: verum end; a2,b2 // b,a by A9, DIRAF:2; then A18: a2,b2 '||' a,b by DIRAF:def_4; b <> a by A1, DIRAF:31; then A19: a2,b2 '||' a9,b9 by A4, A18, DIRAF:23; A20: a,b // b2,a2 by A9, DIRAF:2; Mid b,o,b2 by A8, DIRAF:def_3; then LIN b,o,b2 by DIRAF:28; then A21: LIN o,b,b2 by DIRAF:30; A22: LIN o,b,o by DIRAF:31; o <> b by A1, DIRAF:31; then A23: LIN o,b2,b9 by A3, A21, A22, DIRAF:32; then a2,b2 // b9,a9 by A15, A11, A19, Th7; then A24: b2,a2 // a9,b9 by DIRAF:2; b2,o // o,b9 by A15, A11, A19, A23, Th7; hence o,b // o,b9 by A13, A10, DIRAF:3; ::_thesis: a,b // a9,b9 a2 <> b2 by A15, DIRAF:31; hence a,b // a9,b9 by A20, A24, DIRAF:3; ::_thesis: verum end; theorem Th9: :: PAPDESAF:9 for OAP being OAffinSpace st OAP is satisfying_DES_1 holds Lambda OAP is Desarguesian proof let OAP be OAffinSpace; ::_thesis: ( OAP is satisfying_DES_1 implies Lambda OAP is Desarguesian ) set AP = Lambda OAP; assume A1: OAP is satisfying_DES_1 ; ::_thesis: Lambda OAP is Desarguesian then A2: OAP is satisfying_DES by Th6; for A, P, C being Subset of (Lambda OAP) for o, a, b, c, a9, b9, c9 being Element of (Lambda OAP) st o in A & o in P & o in C & o <> a & o <> b & o <> c & a in A & a9 in A & b in P & b9 in P & c in C & c9 in C & A is being_line & P is being_line & C is being_line & A <> P & A <> C & a,b // a9,b9 & a,c // a9,c9 holds b,c // b9,c9 proof let A, P, C be Subset of (Lambda OAP); ::_thesis: for o, a, b, c, a9, b9, c9 being Element of (Lambda OAP) st o in A & o in P & o in C & o <> a & o <> b & o <> c & a in A & a9 in A & b in P & b9 in P & c in C & c9 in C & A is being_line & P is being_line & C is being_line & A <> P & A <> C & a,b // a9,b9 & a,c // a9,c9 holds b,c // b9,c9 let o, a, b, c, a9, b9, c9 be Element of (Lambda OAP); ::_thesis: ( o in A & o in P & o in C & o <> a & o <> b & o <> c & a in A & a9 in A & b in P & b9 in P & c in C & c9 in C & A is being_line & P is being_line & C is being_line & A <> P & A <> C & a,b // a9,b9 & a,c // a9,c9 implies b,c // b9,c9 ) reconsider o1 = o, a1 = a, b1 = b, c1 = c, a19 = a9, b19 = b9, c19 = c9 as Element of OAP by Th1; assume that A3: o in A and A4: o in P and A5: o in C and A6: o <> a and A7: o <> b and A8: o <> c and A9: a in A and A10: a9 in A and A11: b in P and A12: b9 in P and A13: c in C and A14: c9 in C and A15: A is being_line and A16: P is being_line and A17: C is being_line and A18: A <> P and A19: A <> C and A20: ( a,b // a9,b9 & a,c // a9,c9 ) ; ::_thesis: b,c // b9,c9 LIN o,b,b9 by A4, A11, A12, A16, AFF_1:21; then A21: LIN o1,b1,b19 by Th2; A22: ( not LIN o1,a1,b1 & not LIN o1,a1,c1 ) proof A23: now__::_thesis:_not_LIN_o,a,c assume LIN o,a,c ; ::_thesis: contradiction then consider X being Subset of (Lambda OAP) such that A24: ( X is being_line & o in X ) and A25: a in X and A26: c in X by AFF_1:21; X = C by A5, A8, A13, A17, A24, A26, AFF_1:18; hence contradiction by A3, A6, A9, A15, A19, A24, A25, AFF_1:18; ::_thesis: verum end; A27: now__::_thesis:_not_LIN_o,a,b assume LIN o,a,b ; ::_thesis: contradiction then consider X being Subset of (Lambda OAP) such that A28: ( X is being_line & o in X ) and A29: a in X and A30: b in X by AFF_1:21; X = P by A4, A7, A11, A16, A28, A30, AFF_1:18; hence contradiction by A3, A6, A9, A15, A18, A28, A29, AFF_1:18; ::_thesis: verum end; assume ( LIN o1,a1,b1 or LIN o1,a1,c1 ) ; ::_thesis: contradiction hence contradiction by A27, A23, Th2; ::_thesis: verum end; LIN o,c,c9 by A5, A13, A14, A17, AFF_1:21; then A31: LIN o1,c1,c19 by Th2; A32: ( a1,b1 '||' a19,b19 & a1,c1 '||' a19,c19 ) by A20, DIRAF:38; A33: now__::_thesis:_(_a1,o1_//_o1,a19_implies_b,c_//_b9,c9_) assume A34: a1,o1 // o1,a19 ; ::_thesis: b,c // b9,c9 then A35: ( a1,b1 // b19,a19 & a1,c1 // c19,a19 ) by A21, A31, A22, A32, Th7; ( b1,o1 // o1,b19 & c1,o1 // o1,c19 ) by A21, A31, A22, A32, A34, Th7; then b1,c1 // c19,b19 by A1, A22, A34, A35, Def7; then b1,c1 '||' b19,c19 by DIRAF:def_4; hence b,c // b9,c9 by DIRAF:38; ::_thesis: verum end; A36: now__::_thesis:_(_o1,a1_//_o1,a19_implies_b,c_//_b9,c9_) assume A37: o1,a1 // o1,a19 ; ::_thesis: b,c // b9,c9 then A38: ( a1,b1 // a19,b19 & a1,c1 // a19,c19 ) by A21, A31, A22, A32, Th8; ( o1,b1 // o1,b19 & o1,c1 // o1,c19 ) by A21, A31, A22, A32, A37, Th8; then b1,c1 // b19,c19 by A2, A22, A37, A38, Def6; then b1,c1 '||' b19,c19 by DIRAF:def_4; hence b,c // b9,c9 by DIRAF:38; ::_thesis: verum end; LIN o,a,a9 by A3, A9, A10, A15, AFF_1:21; then LIN o1,a1,a19 by Th2; then ( Mid o1,a1,a19 or Mid a1,o1,a19 or Mid o1,a19,a1 ) by DIRAF:29; hence b,c // b9,c9 by A33, A36, DIRAF:7, DIRAF:def_3; ::_thesis: verum end; hence Lambda OAP is Desarguesian by AFF_2:def_4; ::_thesis: verum end; theorem Th10: :: PAPDESAF:10 for V being RealLinearSpace for o, u, v, u1, v1 being VECTOR of V for r being Real st o - u = r * (u1 - o) & r <> 0 & o,v '||' o,v1 & not o,u '||' o,v & u,v '||' u1,v1 holds ( v1 = u1 + (((- r) ") * (v - u)) & v1 = o + (((- r) ") * (v - o)) & v - u = (- r) * (v1 - u1) ) proof let V be RealLinearSpace; ::_thesis: for o, u, v, u1, v1 being VECTOR of V for r being Real st o - u = r * (u1 - o) & r <> 0 & o,v '||' o,v1 & not o,u '||' o,v & u,v '||' u1,v1 holds ( v1 = u1 + (((- r) ") * (v - u)) & v1 = o + (((- r) ") * (v - o)) & v - u = (- r) * (v1 - u1) ) let o, u, v, u1, v1 be VECTOR of V; ::_thesis: for r being Real st o - u = r * (u1 - o) & r <> 0 & o,v '||' o,v1 & not o,u '||' o,v & u,v '||' u1,v1 holds ( v1 = u1 + (((- r) ") * (v - u)) & v1 = o + (((- r) ") * (v - o)) & v - u = (- r) * (v1 - u1) ) let r be Real; ::_thesis: ( o - u = r * (u1 - o) & r <> 0 & o,v '||' o,v1 & not o,u '||' o,v & u,v '||' u1,v1 implies ( v1 = u1 + (((- r) ") * (v - u)) & v1 = o + (((- r) ") * (v - o)) & v - u = (- r) * (v1 - u1) ) ) assume that A1: o - u = r * (u1 - o) and A2: r <> 0 and A3: o,v '||' o,v1 and A4: not o,u '||' o,v and A5: u,v '||' u1,v1 ; ::_thesis: ( v1 = u1 + (((- r) ") * (v - u)) & v1 = o + (((- r) ") * (v - o)) & v - u = (- r) * (v1 - u1) ) A6: - r <> 0 by A2; for r1, r2 being Real st (r1 * (u - o)) + (r2 * (v - o)) = 0. V holds ( r1 = 0 & r2 = 0 ) proof let r1, r2 be Real; ::_thesis: ( (r1 * (u - o)) + (r2 * (v - o)) = 0. V implies ( r1 = 0 & r2 = 0 ) ) assume (r1 * (u - o)) + (r2 * (v - o)) = 0. V ; ::_thesis: ( r1 = 0 & r2 = 0 ) then A7: r1 * (u - o) = - (r2 * (v - o)) by RLVECT_1:6 .= r2 * (- (v - o)) by RLVECT_1:25 .= (- r2) * (v - o) by RLVECT_1:24 ; assume ( r1 <> 0 or r2 <> 0 ) ; ::_thesis: contradiction then ( r1 <> 0 or - r2 <> 0 ) ; then ( o,u // o,v or o,u // v,o ) by A7, ANALMETR:14; hence contradiction by A4, GEOMTRAP:def_1; ::_thesis: verum end; then reconsider X = OASpace V as OAffinSpace by ANALOAF:26; set w = u1 + (((- r) ") * (v - u)); reconsider p = o, a = u, a1 = u1, b = v, b1 = v1, q = u1 + (((- r) ") * (v - u)) as Element of X by Th3; a,b '||' a1,b1 by A5, Th4; then A8: b,a '||' a1,b1 by DIRAF:22; p,b '||' p,b1 by A3, Th4; then A9: LIN p,b,b1 by DIRAF:def_5; A10: (- r) * ((u1 + (((- r) ") * (v - u))) - u1) = (- r) * (((- r) ") * (v - u)) by RLSUB_2:61 .= ((- r) * ((- r) ")) * (v - u) by RLVECT_1:def_7 .= 1 * (v - u) by A6, XCMPLX_0:def_7 ; then A11: v - u = (- r) * ((u1 + (((- r) ") * (v - u))) - u1) by RLVECT_1:def_8; ( u,v // u1,u1 + (((- r) ") * (v - u)) or u,v // u1 + (((- r) ") * (v - u)),u1 ) by A10, ANALMETR:14; then u,v '||' u1,u1 + (((- r) ") * (v - u)) by GEOMTRAP:def_1; then a,b '||' a1,q by Th4; then A12: b,a '||' a1,q by DIRAF:22; A13: (- r) * (o - (u1 + (((- r) ") * (v - u)))) = ((- r) * o) - ((- r) * (u1 + (((- r) ") * (v - u)))) by RLVECT_1:34 .= ((- r) * o) - (((- r) * u1) + ((- r) * (((- r) ") * (v - u)))) by RLVECT_1:def_5 .= ((- r) * o) - (((- r) * u1) + (((- r) * ((- r) ")) * (v - u))) by RLVECT_1:def_7 .= ((- r) * o) - (((- r) * u1) + (1 * (v - u))) by A6, XCMPLX_0:def_7 .= ((- r) * o) - (((- r) * u1) + (v - u)) by RLVECT_1:def_8 .= (((- r) * o) - ((- r) * u1)) - (v - u) by RLVECT_1:27 .= ((- r) * (o - u1)) - (v - u) by RLVECT_1:34 .= (r * (- (o - u1))) - (v - u) by RLVECT_1:24 .= (o - u) - (v - u) by A1, RLVECT_1:33 .= o - ((v - u) + u) by RLVECT_1:27 .= o - v by RLSUB_2:61 .= 1 * (o - v) by RLVECT_1:def_8 ; then ( v,o // u1 + (((- r) ") * (v - u)),o or v,o // o,u1 + (((- r) ") * (v - u)) ) by ANALMETR:14; then ( o,v // u1 + (((- r) ") * (v - u)),o or o,v // o,u1 + (((- r) ") * (v - u)) ) by ANALOAF:12; then o,v '||' o,u1 + (((- r) ") * (v - u)) by GEOMTRAP:def_1; then p,b '||' p,q by Th4; then A14: LIN p,b,q by DIRAF:def_5; 1 * (u - o) = (- 1) * (- (u - o)) by RLVECT_1:26 .= (- 1) * (r * (u1 - o)) by A1, RLVECT_1:33 .= ((- 1) * r) * (u1 - o) by RLVECT_1:def_7 .= (- r) * (u1 - o) ; then ( o,u // o,u1 or o,u // u1,o ) by ANALMETR:14; then o,u '||' o,u1 by GEOMTRAP:def_1; then p,a '||' p,a1 by Th4; then A15: LIN p,a,a1 by DIRAF:def_5; A16: not LIN p,b,a proof assume LIN p,b,a ; ::_thesis: contradiction then p,b '||' p,a by DIRAF:def_5; then p,a '||' p,b by DIRAF:22; hence contradiction by A4, Th4; ::_thesis: verum end; A17: (- r) * ((u1 + (((- r) ") * (v - u))) - o) = r * (- ((u1 + (((- r) ") * (v - u))) - o)) by RLVECT_1:24 .= r * (o - (u1 + (((- r) ") * (v - u)))) by RLVECT_1:33 .= - (- (r * (o - (u1 + (((- r) ") * (v - u)))))) by RLVECT_1:17 .= - (r * (- (o - (u1 + (((- r) ") * (v - u)))))) by RLVECT_1:25 .= - (1 * (o - v)) by A13, RLVECT_1:24 .= - (o - v) by RLVECT_1:def_8 .= v - o by RLVECT_1:33 ; u1 + (((- r) ") * (v - u)) = o + ((u1 + (((- r) ") * (v - u))) - o) by RLSUB_2:61 .= o + (((- r) ") * (v - o)) by A6, A17, ANALOAF:6 ; hence ( v1 = u1 + (((- r) ") * (v - u)) & v1 = o + (((- r) ") * (v - o)) & v - u = (- r) * (v1 - u1) ) by A11, A16, A9, A14, A15, A12, A8, PASCH:4; ::_thesis: verum end; Lm1: for V being RealLinearSpace for u, v, w being VECTOR of V st u <> v & w <> v & u,v // v,w holds ex r being Real st ( v - u = r * (w - v) & 0 < r ) proof let V be RealLinearSpace; ::_thesis: for u, v, w being VECTOR of V st u <> v & w <> v & u,v // v,w holds ex r being Real st ( v - u = r * (w - v) & 0 < r ) let u, v, w be VECTOR of V; ::_thesis: ( u <> v & w <> v & u,v // v,w implies ex r being Real st ( v - u = r * (w - v) & 0 < r ) ) assume ( u <> v & w <> v & u,v // v,w ) ; ::_thesis: ex r being Real st ( v - u = r * (w - v) & 0 < r ) then consider a, b being Real such that A1: a * (v - u) = b * (w - v) and A2: 0 < a and A3: 0 < b by ANALOAF:7; take r = (a ") * b; ::_thesis: ( v - u = r * (w - v) & 0 < r ) 0 < a " by A2, XREAL_1:122; then A4: 0 * b < r by A3, XREAL_1:68; v - u = 1 * (v - u) by RLVECT_1:def_8 .= ((a ") * a) * (v - u) by A2, XCMPLX_0:def_7 .= (a ") * (b * (w - v)) by A1, RLVECT_1:def_7 .= r * (w - v) by RLVECT_1:def_7 ; hence ( v - u = r * (w - v) & 0 < r ) by A4; ::_thesis: verum end; theorem Th11: :: PAPDESAF:11 for V being RealLinearSpace for OAS being OAffinSpace st OAS = OASpace V holds OAS is satisfying_DES_1 proof let V be RealLinearSpace; ::_thesis: for OAS being OAffinSpace st OAS = OASpace V holds OAS is satisfying_DES_1 let OAS be OAffinSpace; ::_thesis: ( OAS = OASpace V implies OAS is satisfying_DES_1 ) assume A1: OAS = OASpace V ; ::_thesis: OAS is satisfying_DES_1 for o, a, b, c, a1, b1, c1 being Element of OAS st a,o // o,a1 & b,o // o,b1 & c,o // o,c1 & not LIN o,a,b & not LIN o,a,c & a,b // b1,a1 & a,c // c1,a1 holds b,c // c1,b1 proof let o, a, b, c, a1, b1, c1 be Element of OAS; ::_thesis: ( a,o // o,a1 & b,o // o,b1 & c,o // o,c1 & not LIN o,a,b & not LIN o,a,c & a,b // b1,a1 & a,c // c1,a1 implies b,c // c1,b1 ) assume that A2: a,o // o,a1 and A3: b,o // o,b1 and A4: c,o // o,c1 and A5: not LIN o,a,b and A6: not LIN o,a,c and A7: a,b // b1,a1 and A8: a,c // c1,a1 ; ::_thesis: b,c // c1,b1 reconsider y = o, u = a, v = b, w = c, u1 = a1, v1 = b1, w1 = c1 as VECTOR of V by A1, Th3; A9: o <> a by A5, DIRAF:31; A10: now__::_thesis:_(_o_<>_a1_implies_b,c_//_c1,b1_) A11: ( not y,u '||' y,v & not y,u '||' y,w ) proof assume ( y,u '||' y,v or y,u '||' y,w ) ; ::_thesis: contradiction then ( y,u // y,v or y,u // v,y or y,u // y,w or y,u // w,y ) by GEOMTRAP:def_1; then ( o,a // o,b or o,a // b,o or o,a // o,c or o,a // c,o ) by A1, GEOMTRAP:2; then ( o,a '||' o,b or o,a '||' o,c ) by DIRAF:def_4; hence contradiction by A5, A6, DIRAF:def_5; ::_thesis: verum end; o,c // c1,o by A4, DIRAF:2; then y,w // w1,y by A1, GEOMTRAP:2; then A12: y,w '||' y,w1 by GEOMTRAP:def_1; o,b // b1,o by A3, DIRAF:2; then y,v // v1,y by A1, GEOMTRAP:2; then A13: y,v '||' y,v1 by GEOMTRAP:def_1; assume A14: o <> a1 ; ::_thesis: b,c // c1,b1 u,y // y,u1 by A1, A2, GEOMTRAP:2; then consider r being Real such that A15: y - u = r * (u1 - y) and A16: 0 < r by A9, A14, Lm1; u,w // w1,u1 by A1, A8, GEOMTRAP:2; then u,w '||' u1,w1 by GEOMTRAP:def_1; then A17: w1 = u1 + (((- r) ") * (w - u)) by A15, A16, A12, A11, Th10; u,v // v1,u1 by A1, A7, GEOMTRAP:2; then u,v '||' u1,v1 by GEOMTRAP:def_1; then v1 = u1 + (((- r) ") * (v - u)) by A15, A16, A13, A11, Th10; then A18: 1 * (w1 - v1) = (u1 + (((- r) ") * (w - u))) - (u1 + (((- r) ") * (v - u))) by A17, RLVECT_1:def_8 .= (((((- r) ") * (w - u)) + u1) - u1) - (((- r) ") * (v - u)) by RLVECT_1:27 .= (((- r) ") * (w - u)) - (((- r) ") * (v - u)) by RLSUB_2:61 .= ((- r) ") * ((w - u) - (v - u)) by RLVECT_1:34 .= ((- r) ") * (w - ((v - u) + u)) by RLVECT_1:27 .= ((- r) ") * (w - v) by RLSUB_2:61 .= (- (r ")) * (w - v) by XCMPLX_1:222 .= (r ") * (- (w - v)) by RLVECT_1:24 .= (r ") * (v - w) by RLVECT_1:33 ; 0 < r " by A16, XREAL_1:122; then w,v // v1,w1 by A18, ANALOAF:def_1; then c,b // b1,c1 by A1, GEOMTRAP:2; hence b,c // c1,b1 by DIRAF:2; ::_thesis: verum end; now__::_thesis:_(_o_=_a1_implies_b,c_//_c1,b1_) assume A19: o = a1 ; ::_thesis: b,c // c1,b1 A20: o = c1 proof c,o '||' o,c1 by A4, DIRAF:def_4; then o,c1 '||' o,c by DIRAF:22; then A21: LIN o,c1,c by DIRAF:def_5; A22: LIN o,c1,o by DIRAF:31; assume A23: o <> c1 ; ::_thesis: contradiction a,c '||' c1,o by A8, A19, DIRAF:def_4; then o,c1 '||' c,a by DIRAF:22; then LIN o,c1,a by A23, A21, DIRAF:33; hence contradiction by A6, A23, A21, A22, DIRAF:32; ::_thesis: verum end; o = b1 proof b,o '||' o,b1 by A3, DIRAF:def_4; then o,b1 '||' o,b by DIRAF:22; then A24: LIN o,b1,b by DIRAF:def_5; A25: LIN o,b1,o by DIRAF:31; assume A26: o <> b1 ; ::_thesis: contradiction a,b '||' b1,o by A7, A19, DIRAF:def_4; then o,b1 '||' b,a by DIRAF:22; then LIN o,b1,a by A26, A24, DIRAF:33; hence contradiction by A5, A26, A24, A25, DIRAF:32; ::_thesis: verum end; hence b,c // c1,b1 by A20, DIRAF:4; ::_thesis: verum end; hence b,c // c1,b1 by A10; ::_thesis: verum end; hence OAS is satisfying_DES_1 by Def7; ::_thesis: verum end; theorem :: PAPDESAF:12 for V being RealLinearSpace for OAS being OAffinSpace st OAS = OASpace V holds ( OAS is satisfying_DES_1 & OAS is satisfying_DES ) by Th6, Th11; Lm2: for V being RealLinearSpace for y, u, v being VECTOR of V st y,u '||' y,v & y <> u & y <> v holds ex r being Real st ( u - y = r * (v - y) & r <> 0 ) proof let V be RealLinearSpace; ::_thesis: for y, u, v being VECTOR of V st y,u '||' y,v & y <> u & y <> v holds ex r being Real st ( u - y = r * (v - y) & r <> 0 ) let y, u, v be VECTOR of V; ::_thesis: ( y,u '||' y,v & y <> u & y <> v implies ex r being Real st ( u - y = r * (v - y) & r <> 0 ) ) assume that A1: y,u '||' y,v and A2: y <> u and A3: y <> v ; ::_thesis: ex r being Real st ( u - y = r * (v - y) & r <> 0 ) ( y,u // y,v or y,u // v,y ) by A1, GEOMTRAP:def_1; then consider a, b being Real such that A4: a * (u - y) = b * (v - y) and A5: ( a <> 0 or b <> 0 ) by ANALMETR:14; A6: now__::_thesis:_not_b_=_0 assume A7: b = 0 ; ::_thesis: contradiction then 0. V = a * (u - y) by A4, RLVECT_1:10; then u - y = 0. V by A5, A7, RLVECT_1:11; hence contradiction by A2, RLVECT_1:21; ::_thesis: verum end; A8: now__::_thesis:_not_a_=_0 assume A9: a = 0 ; ::_thesis: contradiction then 0. V = b * (v - y) by A4, RLVECT_1:10; then v - y = 0. V by A5, A9, RLVECT_1:11; hence contradiction by A3, RLVECT_1:21; ::_thesis: verum end; then A10: a " <> 0 by XCMPLX_1:202; take r = (a ") * b; ::_thesis: ( u - y = r * (v - y) & r <> 0 ) r * (v - y) = (a ") * (a * (u - y)) by A4, RLVECT_1:def_7 .= ((a ") * a) * (u - y) by RLVECT_1:def_7 .= 1 * (u - y) by A8, XCMPLX_0:def_7 .= u - y by RLVECT_1:def_8 ; hence ( u - y = r * (v - y) & r <> 0 ) by A6, A10, XCMPLX_1:6; ::_thesis: verum end; Lm3: for V being RealLinearSpace for u, v, y being VECTOR of V holds (u - y) - (v - y) = u - v proof let V be RealLinearSpace; ::_thesis: for u, v, y being VECTOR of V holds (u - y) - (v - y) = u - v let u, v, y be VECTOR of V; ::_thesis: (u - y) - (v - y) = u - v thus (u - y) - (v - y) = u - ((v - y) + y) by RLVECT_1:27 .= u - v by RLSUB_2:61 ; ::_thesis: verum end; theorem Th13: :: PAPDESAF:13 for V being RealLinearSpace for OAS being OAffinSpace st OAS = OASpace V holds Lambda OAS is Pappian proof let V be RealLinearSpace; ::_thesis: for OAS being OAffinSpace st OAS = OASpace V holds Lambda OAS is Pappian let OAS be OAffinSpace; ::_thesis: ( OAS = OASpace V implies Lambda OAS is Pappian ) assume A1: OAS = OASpace V ; ::_thesis: Lambda OAS is Pappian set AS = Lambda OAS; for M, N being Subset of (Lambda OAS) for o, a, b, c, a9, b9, c9 being Element of (Lambda OAS) st M is being_line & N is being_line & M <> N & o in M & o in N & o <> a & o <> a9 & o <> b & o <> b9 & o <> c & o <> c9 & a in M & b in M & c in M & a9 in N & b9 in N & c9 in N & a,b9 // b,a9 & b,c9 // c,b9 holds a,c9 // c,a9 proof let M, N be Subset of (Lambda OAS); ::_thesis: for o, a, b, c, a9, b9, c9 being Element of (Lambda OAS) st M is being_line & N is being_line & M <> N & o in M & o in N & o <> a & o <> a9 & o <> b & o <> b9 & o <> c & o <> c9 & a in M & b in M & c in M & a9 in N & b9 in N & c9 in N & a,b9 // b,a9 & b,c9 // c,b9 holds a,c9 // c,a9 let o, a, b, c, a9, b9, c9 be Element of (Lambda OAS); ::_thesis: ( M is being_line & N is being_line & M <> N & o in M & o in N & o <> a & o <> a9 & o <> b & o <> b9 & o <> c & o <> c9 & a in M & b in M & c in M & a9 in N & b9 in N & c9 in N & a,b9 // b,a9 & b,c9 // c,b9 implies a,c9 // c,a9 ) assume that A2: M is being_line and A3: N is being_line and A4: M <> N and A5: o in M and A6: o in N and A7: o <> a and A8: o <> a9 and A9: o <> b and o <> b9 and A10: o <> c and A11: o <> c9 and A12: a in M and A13: b in M and A14: c in M and A15: a9 in N and A16: b9 in N and A17: c9 in N and A18: a,b9 // b,a9 and A19: b,c9 // c,b9 ; ::_thesis: a,c9 // c,a9 reconsider o1 = o, a1 = a, b1 = b, c1 = c, a19 = a9, b19 = b9, c19 = c9 as Element of OAS by Th1; reconsider q = o1, u = a1, v = b1, w = c1, u9 = a19, v9 = b19, w9 = c19 as VECTOR of V by A1, Th3; b1,c19 '||' c1,b19 by A19, DIRAF:38; then A20: v,w9 '||' w,v9 by A1, Th4; A21: ( not q,v '||' q,w9 & not q,v '||' q,u9 ) proof assume ( q,v '||' q,w9 or q,v '||' q,u9 ) ; ::_thesis: contradiction then ( o1,b1 '||' o1,c19 or o1,b1 '||' o1,a19 ) by A1, Th4; then ( o,b // o,c9 or o,b // o,a9 ) by DIRAF:38; then ( LIN o,b,c9 or LIN o,b,a9 ) by AFF_1:def_1; then ( c9 in M or a9 in M ) by A2, A5, A9, A13, AFF_1:25; hence contradiction by A2, A3, A4, A5, A6, A8, A11, A15, A17, AFF_1:18; ::_thesis: verum end; LIN o,c,b by A2, A5, A13, A14, AFF_1:21; then o,c // o,b by AFF_1:def_1; then o1,c1 '||' o1,b1 by DIRAF:38; then q,w '||' q,v by A1, Th4; then consider r2 being Real such that A22: w - q = r2 * (v - q) and A23: r2 <> 0 by A9, A10, Lm2; A24: - r2 <> 0 by A23; LIN o,a,b by A2, A5, A12, A13, AFF_1:21; then o,a // o,b by AFF_1:def_1; then o1,a1 '||' o1,b1 by DIRAF:38; then q,u '||' q,v by A1, Th4; then consider r1 being Real such that A25: u - q = r1 * (v - q) and A26: r1 <> 0 by A7, A9, Lm2; A27: (- r1) * (q - v) = r1 * (- (q - v)) by RLVECT_1:24 .= u - q by A25, RLVECT_1:33 ; LIN o,c9,b9 by A3, A6, A16, A17, AFF_1:21; then o,c9 // o,b9 by AFF_1:def_1; then o1,c19 '||' o1,b19 by DIRAF:38; then A28: q,w9 '||' q,v9 by A1, Th4; (- r2) * (q - v) = r2 * (- (q - v)) by RLVECT_1:24 .= w - q by A22, RLVECT_1:33 ; then A29: q - v = ((- r2) ") * (w - q) by A24, ANALOAF:5; (- r2) " <> 0 by A24, XCMPLX_1:202; then v9 = q + (((- ((- r2) ")) ") * (w9 - q)) by A20, A29, A28, A21, Th10 .= q + (((- (- (r2 "))) ") * (w9 - q)) by XCMPLX_1:222 .= q + (r2 * (w9 - q)) ; then A30: v9 - q = r2 * (w9 - q) by RLSUB_2:61; LIN o,a9,b9 by A3, A6, A15, A16, AFF_1:21; then o,a9 // o,b9 by AFF_1:def_1; then o1,a19 '||' o1,b19 by DIRAF:38; then A31: q,u9 '||' q,v9 by A1, Th4; a1,b19 '||' b1,a19 by A18, DIRAF:38; then b1,a19 '||' a1,b19 by DIRAF:22; then A32: v,u9 '||' u,v9 by A1, Th4; r1 " <> 0 by A26, XCMPLX_1:202; then A33: (r1 ") * r2 <> 0 by A23, XCMPLX_1:6; set s = r1 * (r2 "); A34: u - q = r1 * ((r2 ") * (w - q)) by A25, A22, A23, ANALOAF:6 .= (r1 * (r2 ")) * (w - q) by RLVECT_1:def_7 ; - r1 <> 0 by A26; then A35: (- r1) " <> 0 by XCMPLX_1:202; - r1 <> 0 by A26; then q - v = ((- r1) ") * (u - q) by A27, ANALOAF:6; then v9 = q + (((- ((- r1) ")) ") * (u9 - q)) by A32, A35, A31, A21, Th10 .= q + (((- (- (r1 "))) ") * (u9 - q)) by XCMPLX_1:222 .= q + (r1 * (u9 - q)) ; then v9 - q = r1 * (u9 - q) by RLSUB_2:61; then u9 - q = (r1 ") * (r2 * (w9 - q)) by A26, A30, ANALOAF:6 .= ((r1 ") * r2) * (w9 - q) by RLVECT_1:def_7 ; then A36: w9 - q = (((r1 ") * r2) ") * (u9 - q) by A33, ANALOAF:6 .= (((r1 ") ") * (r2 ")) * (u9 - q) by XCMPLX_1:204 .= (r1 * (r2 ")) * (u9 - q) ; 1 * (w9 - u) = w9 - u by RLVECT_1:def_8 .= ((r1 * (r2 ")) * (u9 - q)) - ((r1 * (r2 ")) * (w - q)) by A36, A34, Lm3 .= (r1 * (r2 ")) * ((u9 - q) - (w - q)) by RLVECT_1:34 .= (r1 * (r2 ")) * (u9 - w) by Lm3 ; then ( u,w9 // w,u9 or u,w9 // u9,w ) by ANALMETR:14; then u,w9 '||' w,u9 by GEOMTRAP:def_1; then a1,c19 '||' c1,a19 by A1, Th4; hence a,c9 // c,a9 by DIRAF:38; ::_thesis: verum end; hence Lambda OAS is Pappian by AFF_2:def_2; ::_thesis: verum end; theorem Th14: :: PAPDESAF:14 for V being RealLinearSpace for OAS being OAffinSpace st OAS = OASpace V holds Lambda OAS is Desarguesian by Th9, Th11; theorem Th15: :: PAPDESAF:15 for AS being AffinSpace st AS is Desarguesian holds AS is Moufangian proof let AS be AffinSpace; ::_thesis: ( AS is Desarguesian implies AS is Moufangian ) assume A1: AS is Desarguesian ; ::_thesis: AS is Moufangian now__::_thesis:_for_K_being_Subset_of_AS for_o,_a,_b,_c,_a9,_b9,_c9_being_Element_of_AS_st_K_is_being_line_&_o_in_K_&_c_in_K_&_c9_in_K_&_not_a_in_K_&_o_<>_c_&_a_<>_b_&_LIN_o,a,a9_&_LIN_o,b,b9_&_a,b_//_a9,b9_&_a,c_//_a9,c9_&_a,b_//_K_holds_ b,c_//_b9,c9 let K be Subset of AS; ::_thesis: for o, a, b, c, a9, b9, c9 being Element of AS st K is being_line & o in K & c in K & c9 in K & not a in K & o <> c & a <> b & LIN o,a,a9 & LIN o,b,b9 & a,b // a9,b9 & a,c // a9,c9 & a,b // K holds b,c // b9,c9 let o, a, b, c, a9, b9, c9 be Element of AS; ::_thesis: ( K is being_line & o in K & c in K & c9 in K & not a in K & o <> c & a <> b & LIN o,a,a9 & LIN o,b,b9 & a,b // a9,b9 & a,c // a9,c9 & a,b // K implies b,c // b9,c9 ) assume that A2: K is being_line and A3: o in K and A4: ( c in K & c9 in K ) and A5: not a in K and A6: o <> c and A7: a <> b and A8: LIN o,a,a9 and A9: LIN o,b,b9 and A10: ( a,b // a9,b9 & a,c // a9,c9 ) and A11: a,b // K ; ::_thesis: b,c // b9,c9 set A = Line (o,a); set P = Line (o,b); A12: o in Line (o,a) by A3, A5, AFF_1:24; A13: now__::_thesis:_not_o_=_b assume A14: o = b ; ::_thesis: contradiction b,a // K by A11, AFF_1:34; hence contradiction by A2, A3, A5, A14, AFF_1:23; ::_thesis: verum end; then A15: b in Line (o,b) by AFF_1:24; A16: a in Line (o,a) by A3, A5, AFF_1:24; A17: Line (o,a) is being_line by A3, A5, AFF_1:24; A18: Line (o,a) <> Line (o,b) proof assume Line (o,a) = Line (o,b) ; ::_thesis: contradiction then a,b // Line (o,a) by A17, A16, A15, AFF_1:40, AFF_1:41; hence contradiction by A3, A5, A7, A11, A12, A16, AFF_1:45, AFF_1:53; ::_thesis: verum end; A19: ( Line (o,b) is being_line & o in Line (o,b) ) by A13, AFF_1:24; then A20: b9 in Line (o,b) by A9, A13, A15, AFF_1:25; a9 in Line (o,a) by A3, A5, A8, A17, A12, A16, AFF_1:25; hence b,c // b9,c9 by A1, A2, A3, A4, A5, A6, A10, A13, A17, A12, A16, A19, A15, A20, A18, AFF_2:def_4; ::_thesis: verum end; hence AS is Moufangian by AFF_2:def_7; ::_thesis: verum end; theorem Th16: :: PAPDESAF:16 for V being RealLinearSpace for OAS being OAffinSpace st OAS = OASpace V holds Lambda OAS is Moufangian proof let V be RealLinearSpace; ::_thesis: for OAS being OAffinSpace st OAS = OASpace V holds Lambda OAS is Moufangian let OAS be OAffinSpace; ::_thesis: ( OAS = OASpace V implies Lambda OAS is Moufangian ) assume OAS = OASpace V ; ::_thesis: Lambda OAS is Moufangian then Lambda OAS is Desarguesian by Th9, Th11; hence Lambda OAS is Moufangian by Th15; ::_thesis: verum end; theorem Th17: :: PAPDESAF:17 for V being RealLinearSpace for OAS being OAffinSpace st OAS = OASpace V holds Lambda OAS is translational proof let V be RealLinearSpace; ::_thesis: for OAS being OAffinSpace st OAS = OASpace V holds Lambda OAS is translational let OAS be OAffinSpace; ::_thesis: ( OAS = OASpace V implies Lambda OAS is translational ) assume A1: OAS = OASpace V ; ::_thesis: Lambda OAS is translational set AS = Lambda OAS; for A, P, C being Subset of (Lambda OAS) for a, b, c, a9, b9, c9 being Element of (Lambda OAS) st A // P & A // C & a in A & a9 in A & b in P & b9 in P & c in C & c9 in C & A is being_line & P is being_line & C is being_line & A <> P & A <> C & a,b // a9,b9 & a,c // a9,c9 holds b,c // b9,c9 proof let A, P, C be Subset of (Lambda OAS); ::_thesis: for a, b, c, a9, b9, c9 being Element of (Lambda OAS) st A // P & A // C & a in A & a9 in A & b in P & b9 in P & c in C & c9 in C & A is being_line & P is being_line & C is being_line & A <> P & A <> C & a,b // a9,b9 & a,c // a9,c9 holds b,c // b9,c9 let a, b, c, a9, b9, c9 be Element of (Lambda OAS); ::_thesis: ( A // P & A // C & a in A & a9 in A & b in P & b9 in P & c in C & c9 in C & A is being_line & P is being_line & C is being_line & A <> P & A <> C & a,b // a9,b9 & a,c // a9,c9 implies b,c // b9,c9 ) assume that A2: A // P and A3: A // C and A4: a in A and A5: a9 in A and A6: b in P and A7: b9 in P and A8: c in C and A9: c9 in C and A10: A is being_line and A11: P is being_line and A12: C is being_line and A13: A <> P and A14: A <> C and A15: a,b // a9,b9 and A16: a,c // a9,c9 ; ::_thesis: b,c // b9,c9 reconsider a1 = a, b1 = b, c1 = c, a19 = a9, b19 = b9, c19 = c9 as Element of OAS by Th1; reconsider u = a1, v = b1, w = c1, u9 = a19 as VECTOR of V by A1, Th3; A17: now__::_thesis:_(_a_<>_a9_implies_b,c_//_b9,c9_) assume A18: a <> a9 ; ::_thesis: b,c // b9,c9 A19: not LIN a1,a19,b1 proof assume LIN a1,a19,b1 ; ::_thesis: contradiction then LIN a,a9,b by Th2; then b in A by A4, A5, A10, A18, AFF_1:25; hence contradiction by A2, A6, A13, AFF_1:45; ::_thesis: verum end; A20: not LIN a1,a19,c1 proof assume LIN a1,a19,c1 ; ::_thesis: contradiction then LIN a,a9,c by Th2; then c in A by A4, A5, A10, A18, AFF_1:25; hence contradiction by A3, A8, A14, AFF_1:45; ::_thesis: verum end; a,a9 // c,c9 by A3, A4, A5, A8, A9, AFF_1:39; then A21: a1,a19 '||' c1,c19 by DIRAF:38; a,a9 // b,b9 by A2, A4, A5, A6, A7, AFF_1:39; then A22: a1,a19 '||' b1,b19 by DIRAF:38; set v99 = (u9 + v) - u; set w99 = (u9 + w) - u; reconsider b199 = (u9 + v) - u, c199 = (u9 + w) - u as Element of OAS by A1, Th3; ((u9 + w) - u) - ((u9 + v) - u) = (u9 + w) - (((u9 + v) - u) + u) by RLVECT_1:27 .= (u9 + w) - (u9 + v) by RLSUB_2:61 .= ((w + u9) - u9) - v by RLVECT_1:27 .= w - v by RLSUB_2:61 ; then v,w // (u9 + v) - u,(u9 + w) - u by ANALOAF:15; then A23: v,w '||' (u9 + v) - u,(u9 + w) - u by GEOMTRAP:def_1; u,u9 // v,(u9 + v) - u by ANALOAF:16; then u,u9 '||' v,(u9 + v) - u by GEOMTRAP:def_1; then A24: a1,a19 '||' b1,b199 by A1, Th4; u,w // u9,(u9 + w) - u by ANALOAF:16; then u,w '||' u9,(u9 + w) - u by GEOMTRAP:def_1; then A25: a1,c1 '||' a19,c199 by A1, Th4; u,u9 // w,(u9 + w) - u by ANALOAF:16; then u,u9 '||' w,(u9 + w) - u by GEOMTRAP:def_1; then A26: a1,a19 '||' c1,c199 by A1, Th4; u,v // u9,(u9 + v) - u by ANALOAF:16; then u,v '||' u9,(u9 + v) - u by GEOMTRAP:def_1; then A27: a1,b1 '||' a19,b199 by A1, Th4; a1,c1 '||' a19,c19 by A16, DIRAF:38; then A28: c199 = c19 by A20, A21, A26, A25, PASCH:5; a1,b1 '||' a19,b19 by A15, DIRAF:38; then b199 = b19 by A19, A22, A24, A27, PASCH:5; then b1,c1 '||' b19,c19 by A1, A28, A23, Th4; hence b,c // b9,c9 by DIRAF:38; ::_thesis: verum end; now__::_thesis:_(_a_=_a9_implies_b,c_//_b9,c9_) assume A29: a = a9 ; ::_thesis: b,c // b9,c9 A30: c = c9 proof LIN a,c,c9 by A16, A29, AFF_1:def_1; then A31: LIN c,c9,a by AFF_1:6; assume c <> c9 ; ::_thesis: contradiction then a in C by A8, A9, A12, A31, AFF_1:25; hence contradiction by A3, A4, A14, AFF_1:45; ::_thesis: verum end; b = b9 proof LIN a,b,b9 by A15, A29, AFF_1:def_1; then A32: LIN b,b9,a by AFF_1:6; assume b <> b9 ; ::_thesis: contradiction then a in P by A6, A7, A11, A32, AFF_1:25; hence contradiction by A2, A4, A13, AFF_1:45; ::_thesis: verum end; hence b,c // b9,c9 by A30, AFF_1:2; ::_thesis: verum end; hence b,c // b9,c9 by A17; ::_thesis: verum end; hence Lambda OAS is translational by AFF_2:def_11; ::_thesis: verum end; theorem Th18: :: PAPDESAF:18 for OAS being OAffinSpace holds Lambda OAS is Fanoian proof let OAS be OAffinSpace; ::_thesis: Lambda OAS is Fanoian set AS = Lambda OAS; for a, b, c, d being Element of (Lambda OAS) st a,b // c,d & a,c // b,d & a,d // b,c holds a,b // a,c proof let a, b, c, d be Element of (Lambda OAS); ::_thesis: ( a,b // c,d & a,c // b,d & a,d // b,c implies a,b // a,c ) assume that A1: a,b // c,d and A2: a,c // b,d and A3: a,d // b,c ; ::_thesis: a,b // a,c reconsider a1 = a, b1 = b, c1 = c, d1 = d as Element of OAS by Th1; set P = Line (a,d); set Q = Line (b,c); assume A4: not a,b // a,c ; ::_thesis: contradiction then A5: a <> d by A1, AFF_1:4; then A6: Line (a,d) is being_line by AFF_1:def_3; A7: not LIN a1,b1,c1 proof assume LIN a1,b1,c1 ; ::_thesis: contradiction then a1,b1 '||' a1,c1 by DIRAF:def_5; hence contradiction by A4, DIRAF:38; ::_thesis: verum end; ( a1,b1 '||' c1,d1 & a1,c1 '||' b1,d1 ) by A1, A2, DIRAF:38; then consider x1 being Element of OAS such that A8: LIN x1,a1,d1 and A9: LIN x1,b1,c1 by A7, PASCH:25; reconsider x = x1 as Element of (Lambda OAS) by Th1; A10: d in Line (a,d) by AFF_1:15; x1,a1 '||' x1,d1 by A8, DIRAF:def_5; then x,a // x,d by DIRAF:38; then LIN x,a,d by AFF_1:def_1; then LIN a,d,x by AFF_1:6; then A11: x in Line (a,d) by AFF_1:def_2; A12: ( a in Line (a,d) & b in Line (b,c) ) by AFF_1:15; x1,b1 '||' x1,c1 by A9, DIRAF:def_5; then x,b // x,c by DIRAF:38; then LIN x,b,c by AFF_1:def_1; then LIN b,c,x by AFF_1:6; then A13: x in Line (b,c) by AFF_1:def_2; A14: c in Line (b,c) by AFF_1:15; A15: not LIN a,b,c by A4, AFF_1:def_1; then A16: b <> c by AFF_1:7; then Line (b,c) is being_line by AFF_1:def_3; then Line (a,d) // Line (b,c) by A3, A16, A5, A6, A10, A12, A14, AFF_1:38; then Line (a,d) = Line (b,c) by A11, A13, AFF_1:45; hence contradiction by A15, A6, A12, A14, AFF_1:21; ::_thesis: verum end; hence Lambda OAS is Fanoian by Def1; ::_thesis: verum end; registration clusterV52() non trivial OAffinSpace-like Pappian Desarguesian Moufangian translation for AffinStruct ; existence ex b1 being OAffinSpace st ( b1 is Pappian & b1 is Desarguesian & b1 is Moufangian & b1 is translation ) proof consider V being RealLinearSpace such that A1: ex u, v being VECTOR of V st for a, b being Real st (a * u) + (b * v) = 0. V holds ( a = 0 & b = 0 ) by FUNCSDOM:23; reconsider X = OASpace V as OAffinSpace by A1, ANALOAF:26; take X ; ::_thesis: ( X is Pappian & X is Desarguesian & X is Moufangian & X is translation ) set AS = Lambda X; A2: ( Lambda X is Moufangian & Lambda X is translational ) by Th16, Th17; ( Lambda X is Pappian & Lambda X is Desarguesian ) by Th9, Th11, Th13; hence ( X is Pappian & X is Desarguesian & X is Moufangian & X is translation ) by A2, Def2, Def3, Def4, Def5; ::_thesis: verum end; end; registration clusterV52() non trivial strict AffinSpace-like 2-dimensional Pappian Desarguesian Moufangian translational Fanoian for AffinStruct ; existence ex b1 being AffinPlane st ( b1 is strict & b1 is Fanoian & b1 is Pappian & b1 is Desarguesian & b1 is Moufangian & b1 is translational ) proof consider V being RealLinearSpace such that A1: ex u, v being VECTOR of V st ( ( for a, b being Real st (a * u) + (b * v) = 0. V holds ( a = 0 & b = 0 ) ) & ( for w being VECTOR of V ex a, b being Real st w = (a * u) + (b * v) ) ) by FUNCSDOM:23; reconsider OAS = OASpace V as OAffinPlane by A1, ANALOAF:28; take X = Lambda OAS; ::_thesis: ( X is strict & X is Fanoian & X is Pappian & X is Desarguesian & X is Moufangian & X is translational ) A2: X is Pappian by Th13; then X is Moufangian by AFF_2:11, AFF_2:12; hence ( X is strict & X is Fanoian & X is Pappian & X is Desarguesian & X is Moufangian & X is translational ) by A2, Th18, AFF_2:11, AFF_2:14; ::_thesis: verum end; end; registration clusterV52() non trivial strict AffinSpace-like Pappian Desarguesian Moufangian translational Fanoian for AffinStruct ; existence ex b1 being AffinSpace st ( b1 is strict & b1 is Fanoian & b1 is Pappian & b1 is Desarguesian & b1 is Moufangian & b1 is translational ) proof consider V being RealLinearSpace such that A1: ex u, v being VECTOR of V st for a, b being Real st (a * u) + (b * v) = 0. V holds ( a = 0 & b = 0 ) by FUNCSDOM:23; reconsider X = OASpace V as OAffinSpace by A1, ANALOAF:26; take Lambda X ; ::_thesis: ( Lambda X is strict & Lambda X is Fanoian & Lambda X is Pappian & Lambda X is Desarguesian & Lambda X is Moufangian & Lambda X is translational ) thus ( Lambda X is strict & Lambda X is Fanoian & Lambda X is Pappian & Lambda X is Desarguesian & Lambda X is Moufangian & Lambda X is translational ) by Th13, Th14, Th16, Th17, Th18; ::_thesis: verum end; end; registration let OAS be OAffinSpace; cluster Lambda OAS -> Fanoian ; correctness coherence Lambda OAS is Fanoian ; by Th18; end; registration let OAS be Pappian OAffinSpace; cluster Lambda OAS -> Pappian ; correctness coherence Lambda OAS is Pappian ; by Def2; end; registration let OAS be Desarguesian OAffinSpace; cluster Lambda OAS -> Desarguesian ; correctness coherence Lambda OAS is Desarguesian ; by Def3; end; registration let OAS be Moufangian OAffinSpace; cluster Lambda OAS -> Moufangian ; correctness coherence Lambda OAS is Moufangian ; by Def4; end; registration let OAS be translation OAffinSpace; cluster Lambda OAS -> translational ; correctness coherence Lambda OAS is translational ; by Def5; end;