:: RUSUB_5 semantic presentation

definition
let c1 be non empty RLSStruct ;
let c2, c3 be Affine Subset of c1;
pred c2 is_parallel_to c3 means :Def1: :: RUSUB_5:def 1
ex b1 being VECTOR of a1 st a2 = a3 + {b1};
end;

:: deftheorem Def1 defines is_parallel_to RUSUB_5:def 1 :
for b1 being non empty RLSStruct
for b2, b3 being Affine Subset of b1 holds
( b2 is_parallel_to b3 iff ex b4 being VECTOR of b1 st b2 = b3 + {b4} );

theorem Th1: :: RUSUB_5:1
for b1 being non empty right_zeroed RLSStruct
for b2 being Affine Subset of b1 holds b2 is_parallel_to b2
proof end;

theorem Th2: :: RUSUB_5:2
for b1 being non empty add-associative right_zeroed right_complementable RLSStruct
for b2, b3 being Affine Subset of b1 st b2 is_parallel_to b3 holds
b3 is_parallel_to b2
proof end;

theorem Th3: :: RUSUB_5:3
for b1 being non empty Abelian add-associative right_zeroed right_complementable RLSStruct
for b2, b3, b4 being Affine Subset of b1 st b2 is_parallel_to b3 & b3 is_parallel_to b4 holds
b2 is_parallel_to b4
proof end;

definition
let c1 be non empty LoopStr ;
let c2, c3 be Subset of c1;
func c2 - c3 -> Subset of a1 equals :: RUSUB_5:def 2
{ (b1 - b2) where B is Element of a1, B is Element of a1 : ( b1 in a2 & b2 in a3 ) } ;
coherence
{ (b1 - b2) where B is Element of c1, B is Element of c1 : ( b1 in c2 & b2 in c3 ) } is Subset of c1
proof end;
end;

:: deftheorem Def2 defines - RUSUB_5:def 2 :
for b1 being non empty LoopStr
for b2, b3 being Subset of b1 holds b2 - b3 = { (b4 - b5) where B is Element of b1, B is Element of b1 : ( b4 in b2 & b5 in b3 ) } ;

theorem Th4: :: RUSUB_5:4
for b1 being RealLinearSpace
for b2, b3 being Affine Subset of b1 holds b2 - b3 is Affine
proof end;

theorem Th5: :: RUSUB_5:5
for b1 being non empty LoopStr
for b2, b3 being Subset of b1 st ( b2 is empty or b3 is empty ) holds
b2 + b3 is empty
proof end;

theorem Th6: :: RUSUB_5:6
for b1 being non empty LoopStr
for b2, b3 being non empty Subset of b1 holds not b2 + b3 is empty
proof end;

theorem Th7: :: RUSUB_5:7
for b1 being non empty LoopStr
for b2, b3 being Subset of b1 st ( b2 is empty or b3 is empty ) holds
b2 - b3 is empty
proof end;

theorem Th8: :: RUSUB_5:8
for b1 being non empty LoopStr
for b2, b3 being non empty Subset of b1 holds not b2 - b3 is empty
proof end;

theorem Th9: :: RUSUB_5:9
for b1 being non empty Abelian add-associative right_zeroed right_complementable LoopStr
for b2, b3 being Subset of b1
for b4 being Element of b1 holds
( b2 = b3 + {b4} iff b2 - {b4} = b3 )
proof end;

theorem Th10: :: RUSUB_5:10
for b1 being non empty Abelian add-associative right_zeroed right_complementable LoopStr
for b2, b3 being Subset of b1
for b4 being Element of b1 st b4 in b3 holds
b2 + {b4} c= b2 + b3
proof end;

theorem Th11: :: RUSUB_5:11
for b1 being non empty Abelian add-associative right_zeroed right_complementable LoopStr
for b2, b3 being Subset of b1
for b4 being Element of b1 st b4 in b3 holds
b2 - {b4} c= b2 - b3
proof end;

theorem Th12: :: RUSUB_5:12
for b1 being RealLinearSpace
for b2 being non empty Subset of b1 holds 0. b1 in b2 - b2
proof end;

theorem Th13: :: RUSUB_5:13
for b1 being RealLinearSpace
for b2 being non empty Affine Subset of b1
for b3 being VECTOR of b1 st b2 is Subspace-like & b3 in b2 holds
b2 + {b3} c= b2
proof end;

theorem Th14: :: RUSUB_5:14
for b1 being RealLinearSpace
for b2, b3, b4 being non empty Affine Subset of b1 st b3 is Subspace-like & b4 is Subspace-like & b2 is_parallel_to b3 & b2 is_parallel_to b4 holds
b3 = b4
proof end;

theorem Th15: :: RUSUB_5:15
for b1 being RealLinearSpace
for b2 being non empty Affine Subset of b1
for b3 being VECTOR of b1 st b3 in b2 holds
0. b1 in b2 - {b3}
proof end;

theorem Th16: :: RUSUB_5:16
for b1 being RealLinearSpace
for b2 being non empty Affine Subset of b1
for b3 being VECTOR of b1 st b3 in b2 holds
ex b4 being non empty Affine Subset of b1 st
( b4 = b2 - {b3} & b2 is_parallel_to b4 & b4 is Subspace-like )
proof end;

theorem Th17: :: RUSUB_5:17
for b1 being RealLinearSpace
for b2 being non empty Affine Subset of b1
for b3, b4 being VECTOR of b1 st b3 in b2 & b4 in b2 holds
b2 - {b4} = b2 - {b3}
proof end;

theorem Th18: :: RUSUB_5:18
for b1 being RealLinearSpace
for b2 being non empty Affine Subset of b1 holds b2 - b2 = union { (b2 - {b3}) where B is VECTOR of b1 : b3 in b2 }
proof end;

theorem Th19: :: RUSUB_5:19
for b1 being RealLinearSpace
for b2 being non empty Affine Subset of b1
for b3 being VECTOR of b1 st b3 in b2 holds
b2 - {b3} = union { (b2 - {b4}) where B is VECTOR of b1 : b4 in b2 }
proof end;

theorem Th20: :: RUSUB_5:20
for b1 being RealLinearSpace
for b2 being non empty Affine Subset of b1 ex b3 being non empty Affine Subset of b1 st
( b3 = b2 - b2 & b3 is Subspace-like & b2 is_parallel_to b3 )
proof end;

definition
let c1 be RealUnitarySpace;
let c2 be Subspace of c1;
func Ort_Comp c2 -> strict Subspace of a1 means :Def3: :: RUSUB_5:def 3
the carrier of a3 = { b1 where B is VECTOR of a1 : for b1 being VECTOR of a1 st b2 in a2 holds
b2,b1 are_orthogonal
}
;
existence
ex b1 being strict Subspace of c1 st the carrier of b1 = { b2 where B is VECTOR of c1 : for b1 being VECTOR of c1 st b3 in c2 holds
b3,b2 are_orthogonal
}
proof end;
uniqueness
for b1, b2 being strict Subspace of c1 st the carrier of b1 = { b3 where B is VECTOR of c1 : for b1 being VECTOR of c1 st b4 in c2 holds
b4,b3 are_orthogonal
}
& the carrier of b2 = { b3 where B is VECTOR of c1 : for b1 being VECTOR of c1 st b4 in c2 holds
b4,b3 are_orthogonal
}
holds
b1 = b2
by RUSUB_1:24;
end;

:: deftheorem Def3 defines Ort_Comp RUSUB_5:def 3 :
for b1 being RealUnitarySpace
for b2 being Subspace of b1
for b3 being strict Subspace of b1 holds
( b3 = Ort_Comp b2 iff the carrier of b3 = { b4 where B is VECTOR of b1 : for b1 being VECTOR of b1 st b5 in b2 holds
b5,b4 are_orthogonal
}
);

definition
let c1 be RealUnitarySpace;
let c2 be non empty Subset of c1;
func Ort_Comp c2 -> strict Subspace of a1 means :Def4: :: RUSUB_5:def 4
the carrier of a3 = { b1 where B is VECTOR of a1 : for b1 being VECTOR of a1 st b2 in a2 holds
b2,b1 are_orthogonal
}
;
existence
ex b1 being strict Subspace of c1 st the carrier of b1 = { b2 where B is VECTOR of c1 : for b1 being VECTOR of c1 st b3 in c2 holds
b3,b2 are_orthogonal
}
proof end;
uniqueness
for b1, b2 being strict Subspace of c1 st the carrier of b1 = { b3 where B is VECTOR of c1 : for b1 being VECTOR of c1 st b4 in c2 holds
b4,b3 are_orthogonal
}
& the carrier of b2 = { b3 where B is VECTOR of c1 : for b1 being VECTOR of c1 st b4 in c2 holds
b4,b3 are_orthogonal
}
holds
b1 = b2
by RUSUB_1:24;
end;

:: deftheorem Def4 defines Ort_Comp RUSUB_5:def 4 :
for b1 being RealUnitarySpace
for b2 being non empty Subset of b1
for b3 being strict Subspace of b1 holds
( b3 = Ort_Comp b2 iff the carrier of b3 = { b4 where B is VECTOR of b1 : for b1 being VECTOR of b1 st b5 in b2 holds
b5,b4 are_orthogonal
}
);

theorem Th21: :: RUSUB_5:21
for b1 being RealUnitarySpace
for b2 being Subspace of b1 holds 0. b1 in Ort_Comp b2
proof end;

theorem Th22: :: RUSUB_5:22
for b1 being RealUnitarySpace holds Ort_Comp ((0). b1) = (Omega). b1
proof end;

theorem Th23: :: RUSUB_5:23
for b1 being RealUnitarySpace holds Ort_Comp ((Omega). b1) = (0). b1
proof end;

theorem Th24: :: RUSUB_5:24
for b1 being RealUnitarySpace
for b2 being Subspace of b1
for b3 being VECTOR of b1 st b3 <> 0. b1 & b3 in b2 holds
not b3 in Ort_Comp b2
proof end;

theorem Th25: :: RUSUB_5:25
for b1 being RealUnitarySpace
for b2 being non empty Subset of b1 holds b2 c= the carrier of (Ort_Comp (Ort_Comp b2))
proof end;

theorem Th26: :: RUSUB_5:26
for b1 being RealUnitarySpace
for b2, b3 being non empty Subset of b1 st b2 c= b3 holds
the carrier of (Ort_Comp b3) c= the carrier of (Ort_Comp b2)
proof end;

theorem Th27: :: RUSUB_5:27
for b1 being RealUnitarySpace
for b2 being Subspace of b1
for b3 being non empty Subset of b1 st b3 = the carrier of b2 holds
Ort_Comp b3 = Ort_Comp b2
proof end;

theorem Th28: :: RUSUB_5:28
for b1 being RealUnitarySpace
for b2 being non empty Subset of b1 holds Ort_Comp b2 = Ort_Comp (Ort_Comp (Ort_Comp b2))
proof end;

theorem Th29: :: RUSUB_5:29
for b1 being RealUnitarySpace
for b2, b3 being VECTOR of b1 holds
( ||.(b2 + b3).|| ^2 = ((||.b2.|| ^2 ) + (2 * (b2 .|. b3))) + (||.b3.|| ^2 ) & ||.(b2 - b3).|| ^2 = ((||.b2.|| ^2 ) - (2 * (b2 .|. b3))) + (||.b3.|| ^2 ) )
proof end;

theorem Th30: :: RUSUB_5:30
for b1 being RealUnitarySpace
for b2, b3 being VECTOR of b1 st b2,b3 are_orthogonal holds
||.(b2 + b3).|| ^2 = (||.b2.|| ^2 ) + (||.b3.|| ^2 )
proof end;

theorem Th31: :: RUSUB_5:31
for b1 being RealUnitarySpace
for b2, b3 being VECTOR of b1 holds (||.(b2 + b3).|| ^2 ) + (||.(b2 - b3).|| ^2 ) = (2 * (||.b2.|| ^2 )) + (2 * (||.b3.|| ^2 ))
proof end;

theorem Th32: :: RUSUB_5:32
for b1 being RealUnitarySpace
for b2 being VECTOR of b1 ex b3 being Subspace of b1 st the carrier of b3 = { b4 where B is VECTOR of b1 : b4 .|. b2 = 0 }
proof end;

definition
let c1 be RealUnitarySpace;
func Family_open_set c1 -> Subset-Family of a1 means :Def5: :: RUSUB_5:def 5
for b1 being Subset of a1 holds
( b1 in a2 iff for b2 being Point of a1 st b2 in b1 holds
ex b3 being Real st
( b3 > 0 & Ball b2,b3 c= b1 ) );
existence
ex b1 being Subset-Family of c1 st
for b2 being Subset of c1 holds
( b2 in b1 iff for b3 being Point of c1 st b3 in b2 holds
ex b4 being Real st
( b4 > 0 & Ball b3,b4 c= b2 ) )
proof end;
uniqueness
for b1, b2 being Subset-Family of c1 st ( for b3 being Subset of c1 holds
( b3 in b1 iff for b4 being Point of c1 st b4 in b3 holds
ex b5 being Real st
( b5 > 0 & Ball b4,b5 c= b3 ) ) ) & ( for b3 being Subset of c1 holds
( b3 in b2 iff for b4 being Point of c1 st b4 in b3 holds
ex b5 being Real st
( b5 > 0 & Ball b4,b5 c= b3 ) ) ) holds
b1 = b2
proof end;
end;

:: deftheorem Def5 defines Family_open_set RUSUB_5:def 5 :
for b1 being RealUnitarySpace
for b2 being Subset-Family of b1 holds
( b2 = Family_open_set b1 iff for b3 being Subset of b1 holds
( b3 in b2 iff for b4 being Point of b1 st b4 in b3 holds
ex b5 being Real st
( b5 > 0 & Ball b4,b5 c= b3 ) ) );

theorem Th33: :: RUSUB_5:33
for b1 being RealUnitarySpace
for b2 being Point of b1
for b3, b4 being Real st b3 <= b4 holds
Ball b2,b3 c= Ball b2,b4
proof end;

theorem Th34: :: RUSUB_5:34
for b1 being RealUnitarySpace
for b2 being Point of b1 ex b3 being Real st
( b3 > 0 & Ball b2,b3 c= the carrier of b1 )
proof end;

theorem Th35: :: RUSUB_5:35
for b1 being RealUnitarySpace
for b2, b3 being Point of b1
for b4 being Real st b3 in Ball b2,b4 holds
ex b5 being Real st
( b5 > 0 & Ball b3,b5 c= Ball b2,b4 )
proof end;

theorem Th36: :: RUSUB_5:36
for b1 being RealUnitarySpace
for b2, b3, b4 being Point of b1
for b5, b6 being Real st b3 in (Ball b2,b5) /\ (Ball b4,b6) holds
ex b7 being Real st
( Ball b3,b7 c= Ball b2,b5 & Ball b3,b7 c= Ball b4,b6 )
proof end;

theorem Th37: :: RUSUB_5:37
for b1 being RealUnitarySpace
for b2 being Point of b1
for b3 being Real holds Ball b2,b3 in Family_open_set b1
proof end;

theorem Th38: :: RUSUB_5:38
for b1 being RealUnitarySpace holds the carrier of b1 in Family_open_set b1
proof end;

theorem Th39: :: RUSUB_5:39
for b1 being RealUnitarySpace
for b2, b3 being Subset of b1 st b2 in Family_open_set b1 & b3 in Family_open_set b1 holds
b2 /\ b3 in Family_open_set b1
proof end;

theorem Th40: :: RUSUB_5:40
for b1 being RealUnitarySpace
for b2 being Subset-Family of b1 st b2 c= Family_open_set b1 holds
union b2 in Family_open_set b1
proof end;

theorem Th41: :: RUSUB_5:41
for b1 being RealUnitarySpace holds TopStruct(# the carrier of b1,(Family_open_set b1) #) is TopSpace
proof end;

definition
let c1 be RealUnitarySpace;
func TopUnitSpace c1 -> TopStruct equals :: RUSUB_5:def 6
TopStruct(# the carrier of a1,(Family_open_set a1) #);
coherence
TopStruct(# the carrier of c1,(Family_open_set c1) #) is TopStruct
;
end;

:: deftheorem Def6 defines TopUnitSpace RUSUB_5:def 6 :
for b1 being RealUnitarySpace holds TopUnitSpace b1 = TopStruct(# the carrier of b1,(Family_open_set b1) #);

registration
let c1 be RealUnitarySpace;
cluster TopUnitSpace a1 -> TopSpace-like ;
coherence
TopUnitSpace c1 is TopSpace-like
by Th41;
end;

registration
let c1 be RealUnitarySpace;
cluster TopUnitSpace a1 -> non empty TopSpace-like ;
coherence
not TopUnitSpace c1 is empty
;
end;

theorem Th42: :: RUSUB_5:42
for b1 being RealUnitarySpace
for b2 being Subset of (TopUnitSpace b1) st b2 = [#] b1 holds
( b2 is open & b2 is closed )
proof end;

theorem Th43: :: RUSUB_5:43
for b1 being RealUnitarySpace
for b2 being Subset of (TopUnitSpace b1) st b2 = {} b1 holds
( b2 is open & b2 is closed )
proof end;

theorem Th44: :: RUSUB_5:44
for b1 being RealUnitarySpace
for b2 being VECTOR of b1
for b3 being Real st the carrier of b1 = {(0. b1)} & b3 <> 0 holds
Sphere b2,b3 is empty
proof end;

theorem Th45: :: RUSUB_5:45
for b1 being RealUnitarySpace
for b2 being VECTOR of b1
for b3 being Real st the carrier of b1 <> {(0. b1)} & b3 > 0 holds
not Sphere b2,b3 is empty
proof end;

theorem Th46: :: RUSUB_5:46
for b1 being RealUnitarySpace
for b2 being VECTOR of b1
for b3 being Real st b3 = 0 holds
Ball b2,b3 is empty
proof end;

theorem Th47: :: RUSUB_5:47
for b1 being RealUnitarySpace
for b2 being VECTOR of b1
for b3 being Real st the carrier of b1 = {(0. b1)} & b3 > 0 holds
Ball b2,b3 = {(0. b1)}
proof end;

theorem Th48: :: RUSUB_5:48
for b1 being RealUnitarySpace
for b2 being VECTOR of b1
for b3 being Real st the carrier of b1 <> {(0. b1)} & b3 > 0 holds
ex b4 being VECTOR of b1 st
( b4 <> b2 & b4 in Ball b2,b3 )
proof end;

theorem Th49: :: RUSUB_5:49
for b1 being RealUnitarySpace holds
( the carrier of b1 = the carrier of (TopUnitSpace b1) & the topology of (TopUnitSpace b1) = Family_open_set b1 ) ;

theorem Th50: :: RUSUB_5:50
for b1 being RealUnitarySpace
for b2 being Subset of (TopUnitSpace b1)
for b3 being Real
for b4 being Point of b1 st b2 = Ball b4,b3 holds
b2 is open
proof end;

theorem Th51: :: RUSUB_5:51
for b1 being RealUnitarySpace
for b2 being Subset of (TopUnitSpace b1) holds
( b2 is open iff for b3 being Point of b1 st b3 in b2 holds
ex b4 being Real st
( b4 > 0 & Ball b3,b4 c= b2 ) )
proof end;

theorem Th52: :: RUSUB_5:52
for b1 being RealUnitarySpace
for b2, b3 being Point of b1
for b4, b5 being Real ex b6 being Point of b1ex b7 being Real st (Ball b2,b4) \/ (Ball b3,b5) c= Ball b6,b7
proof end;

theorem Th53: :: RUSUB_5:53
for b1 being RealUnitarySpace
for b2 being Subset of (TopUnitSpace b1)
for b3 being VECTOR of b1
for b4 being Real st b2 = cl_Ball b3,b4 holds
b2 is closed
proof end;

theorem Th54: :: RUSUB_5:54
for b1 being RealUnitarySpace
for b2 being Subset of (TopUnitSpace b1)
for b3 being VECTOR of b1
for b4 being Real st b2 = Sphere b3,b4 holds
b2 is closed
proof end;