:: TEX_4 semantic presentation

registration
let c1 be non empty TopSpace;
let c2 be non empty Subset of c1;
cluster Cl a2 -> non empty ;
coherence
not Cl c2 is empty
by PCOMPS_1:2;
end;

registration
let c1 be non empty TopSpace;
let c2 be empty Subset of c1;
cluster Cl a2 -> empty ;
coherence
Cl c2 is empty
by PRE_TOPC:52;
end;

registration
let c1 be non empty TopSpace;
let c2 be non proper Subset of c1;
cluster Cl a2 -> non empty non proper ;
coherence
not Cl c2 is proper
proof end;
end;

registration
let c1 be non empty non trivial TopSpace;
let c2 be non empty non trivial Subset of c1;
cluster Cl a2 -> non empty non trivial ;
coherence
not Cl c2 is trivial
proof end;
end;

theorem Th1: :: TEX_4:1
for b1 being non empty TopSpace
for b2 being Subset of b1 holds Cl b2 = meet { b3 where B is Subset of b1 : ( b3 is closed & b2 c= b3 ) }
proof end;

theorem Th2: :: TEX_4:2
for b1 being non empty TopSpace
for b2 being Point of b1 holds Cl {b2} = meet { b3 where B is Subset of b1 : ( b3 is closed & b2 in b3 ) }
proof end;

registration
let c1 be non empty TopSpace;
let c2 be non proper Subset of c1;
cluster Int a2 -> non proper ;
coherence
not Int c2 is proper
proof end;
end;

registration
let c1 be non empty TopSpace;
let c2 be proper Subset of c1;
cluster Int a2 -> proper ;
coherence
Int c2 is proper
proof end;
end;

registration
let c1 be non empty TopSpace;
let c2 be empty Subset of c1;
cluster Int a2 -> empty proper ;
coherence
Int c2 is empty
;
end;

theorem Th3: :: TEX_4:3
canceled;

theorem Th4: :: TEX_4:4
for b1 being non empty TopSpace
for b2 being Subset of b1 holds Int b2 = union { b3 where B is Subset of b1 : ( b3 is open & b3 c= b2 ) }
proof end;

definition
let c1 be TopStruct ;
let c2 be Subset of c1;
attr a2 is anti-discrete means :Def1: :: TEX_4:def 1
for b1 being Point of a1
for b2 being Subset of a1 st b2 is open & b1 in b2 & b1 in a2 holds
a2 c= b2;
end;

:: deftheorem Def1 defines anti-discrete TEX_4:def 1 :
for b1 being TopStruct
for b2 being Subset of b1 holds
( b2 is anti-discrete iff for b3 being Point of b1
for b4 being Subset of b1 st b4 is open & b3 in b4 & b3 in b2 holds
b2 c= b4 );

definition
let c1 be non empty TopStruct ;
let c2 be Subset of c1;
redefine attr a2 is anti-discrete means :Def2: :: TEX_4:def 2
for b1 being Point of a1
for b2 being Subset of a1 st b2 is closed & b1 in b2 & b1 in a2 holds
a2 c= b2;
compatibility
( c2 is anti-discrete iff for b1 being Point of c1
for b2 being Subset of c1 st b2 is closed & b1 in b2 & b1 in c2 holds
c2 c= b2 )
proof end;
end;

:: deftheorem Def2 defines anti-discrete TEX_4:def 2 :
for b1 being non empty TopStruct
for b2 being Subset of b1 holds
( b2 is anti-discrete iff for b3 being Point of b1
for b4 being Subset of b1 st b4 is closed & b3 in b4 & b3 in b2 holds
b2 c= b4 );

definition
let c1 be TopStruct ;
let c2 be Subset of c1;
redefine attr a2 is anti-discrete means :Def3: :: TEX_4:def 3
for b1 being Subset of a1 holds
( not b1 is open or a2 misses b1 or a2 c= b1 );
compatibility
( c2 is anti-discrete iff for b1 being Subset of c1 holds
( not b1 is open or c2 misses b1 or c2 c= b1 ) )
proof end;
end;

:: deftheorem Def3 defines anti-discrete TEX_4:def 3 :
for b1 being TopStruct
for b2 being Subset of b1 holds
( b2 is anti-discrete iff for b3 being Subset of b1 holds
( not b3 is open or b2 misses b3 or b2 c= b3 ) );

definition
let c1 be TopStruct ;
let c2 be Subset of c1;
redefine attr a2 is anti-discrete means :Def4: :: TEX_4:def 4
for b1 being Subset of a1 holds
( not b1 is closed or a2 misses b1 or a2 c= b1 );
compatibility
( c2 is anti-discrete iff for b1 being Subset of c1 holds
( not b1 is closed or c2 misses b1 or c2 c= b1 ) )
proof end;
end;

:: deftheorem Def4 defines anti-discrete TEX_4:def 4 :
for b1 being TopStruct
for b2 being Subset of b1 holds
( b2 is anti-discrete iff for b3 being Subset of b1 holds
( not b3 is closed or b2 misses b3 or b2 c= b3 ) );

theorem Th5: :: TEX_4:5
canceled;

theorem Th6: :: TEX_4:6
for b1, b2 being TopStruct
for b3 being Subset of b1
for b4 being Subset of b2 st TopStruct(# the carrier of b1,the topology of b1 #) = TopStruct(# the carrier of b2,the topology of b2 #) & b3 = b4 & b3 is anti-discrete holds
b4 is anti-discrete
proof end;

theorem Th7: :: TEX_4:7
for b1 being non empty TopStruct
for b2, b3 being Subset of b1 st b3 c= b2 & b2 is anti-discrete holds
b3 is anti-discrete
proof end;

theorem Th8: :: TEX_4:8
for b1 being non empty TopStruct
for b2 being Point of b1 holds {b2} is anti-discrete
proof end;

theorem Th9: :: TEX_4:9
for b1 being non empty TopStruct
for b2 being empty Subset of b1 holds b2 is anti-discrete
proof end;

definition
let c1 be TopStruct ;
let c2 be Subset-Family of c1;
attr a2 is anti-discrete-set-family means :Def5: :: TEX_4:def 5
for b1 being Subset of a1 st b1 in a2 holds
b1 is anti-discrete;
end;

:: deftheorem Def5 defines anti-discrete-set-family TEX_4:def 5 :
for b1 being TopStruct
for b2 being Subset-Family of b1 holds
( b2 is anti-discrete-set-family iff for b3 being Subset of b1 st b3 in b2 holds
b3 is anti-discrete );

theorem Th10: :: TEX_4:10
for b1 being non empty TopStruct
for b2 being Subset-Family of b1 st b2 is anti-discrete-set-family & meet b2 <> {} holds
union b2 is anti-discrete
proof end;

theorem Th11: :: TEX_4:11
for b1 being non empty TopStruct
for b2 being Subset-Family of b1 st b2 is anti-discrete-set-family holds
meet b2 is anti-discrete
proof end;

definition
let c1 be TopStruct ;
let c2 be Point of c1;
func MaxADSF c2 -> Subset-Family of a1 equals :: TEX_4:def 6
{ b1 where B is Subset of a1 : ( b1 is anti-discrete & a2 in b1 ) } ;
coherence
{ b1 where B is Subset of c1 : ( b1 is anti-discrete & c2 in b1 ) } is Subset-Family of c1
proof end;
end;

:: deftheorem Def6 defines MaxADSF TEX_4:def 6 :
for b1 being TopStruct
for b2 being Point of b1 holds MaxADSF b2 = { b3 where B is Subset of b1 : ( b3 is anti-discrete & b2 in b3 ) } ;

registration
let c1 be non empty TopStruct ;
let c2 be Point of c1;
cluster MaxADSF a2 -> non empty ;
coherence
not MaxADSF c2 is empty
proof end;
end;

theorem Th12: :: TEX_4:12
for b1 being non empty TopStruct
for b2 being Point of b1 holds MaxADSF b2 is anti-discrete-set-family
proof end;

theorem Th13: :: TEX_4:13
for b1 being non empty TopStruct
for b2 being Point of b1 holds {b2} = meet (MaxADSF b2)
proof end;

theorem Th14: :: TEX_4:14
for b1 being non empty TopStruct
for b2 being Point of b1 holds {b2} c= union (MaxADSF b2)
proof end;

theorem Th15: :: TEX_4:15
for b1 being non empty TopStruct
for b2 being Point of b1 holds union (MaxADSF b2) is anti-discrete
proof end;

definition
let c1 be TopStruct ;
let c2 be Subset of c1;
attr a2 is maximal_anti-discrete means :Def7: :: TEX_4:def 7
( a2 is anti-discrete & ( for b1 being Subset of a1 st b1 is anti-discrete & a2 c= b1 holds
a2 = b1 ) );
end;

:: deftheorem Def7 defines maximal_anti-discrete TEX_4:def 7 :
for b1 being TopStruct
for b2 being Subset of b1 holds
( b2 is maximal_anti-discrete iff ( b2 is anti-discrete & ( for b3 being Subset of b1 st b3 is anti-discrete & b2 c= b3 holds
b2 = b3 ) ) );

theorem Th16: :: TEX_4:16
for b1, b2 being TopStruct
for b3 being Subset of b1
for b4 being Subset of b2 st TopStruct(# the carrier of b1,the topology of b1 #) = TopStruct(# the carrier of b2,the topology of b2 #) & b3 = b4 & b3 is maximal_anti-discrete holds
b4 is maximal_anti-discrete
proof end;

theorem Th17: :: TEX_4:17
for b1 being non empty TopStruct
for b2 being empty Subset of b1 holds not b2 is maximal_anti-discrete
proof end;

theorem Th18: :: TEX_4:18
for b1 being non empty TopStruct
for b2 being non empty Subset of b1 st b2 is anti-discrete & b2 is open holds
b2 is maximal_anti-discrete
proof end;

theorem Th19: :: TEX_4:19
for b1 being non empty TopStruct
for b2 being non empty Subset of b1 st b2 is anti-discrete & b2 is closed holds
b2 is maximal_anti-discrete
proof end;

definition
let c1 be TopStruct ;
let c2 be Point of c1;
func MaxADSet c2 -> Subset of a1 equals :: TEX_4:def 8
union (MaxADSF a2);
coherence
union (MaxADSF c2) is Subset of c1
;
end;

:: deftheorem Def8 defines MaxADSet TEX_4:def 8 :
for b1 being TopStruct
for b2 being Point of b1 holds MaxADSet b2 = union (MaxADSF b2);

registration
let c1 be non empty TopStruct ;
let c2 be Point of c1;
cluster MaxADSet a2 -> non empty ;
coherence
not MaxADSet c2 is empty
proof end;
end;

theorem Th20: :: TEX_4:20
for b1 being non empty TopStruct
for b2 being Point of b1 holds {b2} c= MaxADSet b2 by Th14;

theorem Th21: :: TEX_4:21
for b1 being non empty TopStruct
for b2 being Subset of b1
for b3 being Point of b1 st b2 is anti-discrete & b3 in b2 holds
b2 c= MaxADSet b3
proof end;

theorem Th22: :: TEX_4:22
for b1 being non empty TopStruct
for b2 being Point of b1 holds MaxADSet b2 is maximal_anti-discrete
proof end;

theorem Th23: :: TEX_4:23
for b1 being non empty TopStruct
for b2, b3 being Point of b1 holds
( b3 in MaxADSet b2 iff MaxADSet b3 = MaxADSet b2 )
proof end;

theorem Th24: :: TEX_4:24
for b1 being non empty TopStruct
for b2, b3 being Point of b1 holds
( MaxADSet b2 misses MaxADSet b3 or MaxADSet b2 = MaxADSet b3 )
proof end;

theorem Th25: :: TEX_4:25
for b1 being non empty TopStruct
for b2 being Subset of b1
for b3 being Point of b1 st b2 is closed & b3 in b2 holds
MaxADSet b3 c= b2
proof end;

theorem Th26: :: TEX_4:26
for b1 being non empty TopStruct
for b2 being Subset of b1
for b3 being Point of b1 st b2 is open & b3 in b2 holds
MaxADSet b3 c= b2
proof end;

theorem Th27: :: TEX_4:27
for b1 being non empty TopStruct
for b2 being Point of b1 st { b3 where B is Subset of b1 : ( b3 is closed & b2 in b3 ) } <> {} holds
MaxADSet b2 c= meet { b3 where B is Subset of b1 : ( b3 is closed & b2 in b3 ) }
proof end;

theorem Th28: :: TEX_4:28
for b1 being non empty TopStruct
for b2 being Point of b1 st { b3 where B is Subset of b1 : ( b3 is open & b2 in b3 ) } <> {} holds
MaxADSet b2 c= meet { b3 where B is Subset of b1 : ( b3 is open & b2 in b3 ) }
proof end;

definition
let c1 be non empty TopStruct ;
let c2 be Subset of c1;
redefine attr a2 is maximal_anti-discrete means :Def9: :: TEX_4:def 9
ex b1 being Point of a1 st
( b1 in a2 & a2 = MaxADSet b1 );
compatibility
( c2 is maximal_anti-discrete iff ex b1 being Point of c1 st
( b1 in c2 & c2 = MaxADSet b1 ) )
proof end;
end;

:: deftheorem Def9 defines maximal_anti-discrete TEX_4:def 9 :
for b1 being non empty TopStruct
for b2 being Subset of b1 holds
( b2 is maximal_anti-discrete iff ex b3 being Point of b1 st
( b3 in b2 & b2 = MaxADSet b3 ) );

theorem Th29: :: TEX_4:29
for b1 being non empty TopStruct
for b2 being Subset of b1
for b3 being Point of b1 st b3 in b2 & b2 is maximal_anti-discrete holds
b2 = MaxADSet b3
proof end;

definition
let c1 be non empty TopStruct ;
let c2 be non empty Subset of c1;
redefine attr a2 is maximal_anti-discrete means :: TEX_4:def 10
for b1 being Point of a1 st b1 in a2 holds
a2 = MaxADSet b1;
compatibility
( c2 is maximal_anti-discrete iff for b1 being Point of c1 st b1 in c2 holds
c2 = MaxADSet b1 )
proof end;
end;

:: deftheorem Def10 defines maximal_anti-discrete TEX_4:def 10 :
for b1 being non empty TopStruct
for b2 being non empty Subset of b1 holds
( b2 is maximal_anti-discrete iff for b3 being Point of b1 st b3 in b2 holds
b2 = MaxADSet b3 );

definition
let c1 be non empty TopStruct ;
let c2 be Subset of c1;
func MaxADSet c2 -> Subset of a1 equals :: TEX_4:def 11
union { (MaxADSet b1) where B is Point of a1 : b1 in a2 } ;
coherence
union { (MaxADSet b1) where B is Point of c1 : b1 in c2 } is Subset of c1
proof end;
end;

:: deftheorem Def11 defines MaxADSet TEX_4:def 11 :
for b1 being non empty TopStruct
for b2 being Subset of b1 holds MaxADSet b2 = union { (MaxADSet b3) where B is Point of b1 : b3 in b2 } ;

theorem Th30: :: TEX_4:30
for b1 being non empty TopStruct
for b2 being Point of b1 holds MaxADSet b2 = MaxADSet {b2}
proof end;

theorem Th31: :: TEX_4:31
for b1 being non empty TopStruct
for b2 being Subset of b1
for b3 being Point of b1 st MaxADSet b3 meets MaxADSet b2 holds
MaxADSet b3 meets b2
proof end;

theorem Th32: :: TEX_4:32
for b1 being non empty TopStruct
for b2 being Subset of b1
for b3 being Point of b1 st MaxADSet b3 meets MaxADSet b2 holds
MaxADSet b3 c= MaxADSet b2
proof end;

theorem Th33: :: TEX_4:33
for b1 being non empty TopStruct
for b2, b3 being Subset of b1 st b2 c= b3 holds
MaxADSet b2 c= MaxADSet b3
proof end;

theorem Th34: :: TEX_4:34
for b1 being non empty TopStruct
for b2 being Subset of b1 holds b2 c= MaxADSet b2
proof end;

theorem Th35: :: TEX_4:35
for b1 being non empty TopStruct
for b2 being Subset of b1 holds MaxADSet b2 = MaxADSet (MaxADSet b2)
proof end;

theorem Th36: :: TEX_4:36
for b1 being non empty TopStruct
for b2, b3 being Subset of b1 st b2 c= MaxADSet b3 holds
MaxADSet b2 c= MaxADSet b3
proof end;

theorem Th37: :: TEX_4:37
for b1 being non empty TopStruct
for b2, b3 being Subset of b1 holds
( ( b3 c= MaxADSet b2 & b2 c= MaxADSet b3 ) iff MaxADSet b2 = MaxADSet b3 )
proof end;

theorem Th38: :: TEX_4:38
for b1 being non empty TopStruct
for b2, b3 being Subset of b1 holds MaxADSet (b2 \/ b3) = (MaxADSet b2) \/ (MaxADSet b3)
proof end;

theorem Th39: :: TEX_4:39
for b1 being non empty TopStruct
for b2, b3 being Subset of b1 holds MaxADSet (b2 /\ b3) c= (MaxADSet b2) /\ (MaxADSet b3)
proof end;

registration
let c1 be non empty TopStruct ;
let c2 be non empty Subset of c1;
cluster MaxADSet a2 -> non empty ;
coherence
not MaxADSet c2 is empty
proof end;
end;

registration
let c1 be non empty TopStruct ;
let c2 be empty Subset of c1;
cluster MaxADSet a2 -> empty ;
coherence
MaxADSet c2 is empty
proof end;
end;

registration
let c1 be non empty TopStruct ;
let c2 be non proper Subset of c1;
cluster MaxADSet a2 -> non empty non proper ;
coherence
not MaxADSet c2 is proper
proof end;
end;

registration
let c1 be non empty non trivial TopStruct ;
let c2 be non empty non trivial Subset of c1;
cluster MaxADSet a2 -> non empty non trivial ;
coherence
not MaxADSet c2 is trivial
proof end;
end;

theorem Th40: :: TEX_4:40
for b1 being non empty TopStruct
for b2, b3 being Subset of b1 st b2 is open & b3 c= b2 holds
MaxADSet b3 c= b2
proof end;

theorem Th41: :: TEX_4:41
for b1 being non empty TopStruct
for b2 being Subset of b1 st { b3 where B is Subset of b1 : ( b3 is open & b2 c= b3 ) } <> {} holds
MaxADSet b2 c= meet { b3 where B is Subset of b1 : ( b3 is open & b2 c= b3 ) }
proof end;

theorem Th42: :: TEX_4:42
for b1 being non empty TopStruct
for b2, b3 being Subset of b1 st b2 is closed & b3 c= b2 holds
MaxADSet b3 c= b2
proof end;

theorem Th43: :: TEX_4:43
for b1 being non empty TopStruct
for b2 being Subset of b1 st { b3 where B is Subset of b1 : ( b3 is closed & b2 c= b3 ) } <> {} holds
MaxADSet b2 c= meet { b3 where B is Subset of b1 : ( b3 is closed & b2 c= b3 ) }
proof end;

definition
let c1 be non empty TopSpace;
let c2 be Subset of c1;
redefine attr a2 is anti-discrete means :Def12: :: TEX_4:def 12
for b1 being Point of a1 st b1 in a2 holds
a2 c= Cl {b1};
compatibility
( c2 is anti-discrete iff for b1 being Point of c1 st b1 in c2 holds
c2 c= Cl {b1} )
proof end;
end;

:: deftheorem Def12 defines anti-discrete TEX_4:def 12 :
for b1 being non empty TopSpace
for b2 being Subset of b1 holds
( b2 is anti-discrete iff for b3 being Point of b1 st b3 in b2 holds
b2 c= Cl {b3} );

definition
let c1 be non empty TopSpace;
let c2 be Subset of c1;
redefine attr a2 is anti-discrete means :: TEX_4:def 13
for b1 being Point of a1 st b1 in a2 holds
Cl a2 = Cl {b1};
compatibility
( c2 is anti-discrete iff for b1 being Point of c1 st b1 in c2 holds
Cl c2 = Cl {b1} )
proof end;
end;

:: deftheorem Def13 defines anti-discrete TEX_4:def 13 :
for b1 being non empty TopSpace
for b2 being Subset of b1 holds
( b2 is anti-discrete iff for b3 being Point of b1 st b3 in b2 holds
Cl b2 = Cl {b3} );

definition
let c1 be non empty TopSpace;
let c2 be Subset of c1;
redefine attr a2 is anti-discrete means :Def14: :: TEX_4:def 14
for b1, b2 being Point of a1 st b1 in a2 & b2 in a2 holds
Cl {b1} = Cl {b2};
compatibility
( c2 is anti-discrete iff for b1, b2 being Point of c1 st b1 in c2 & b2 in c2 holds
Cl {b1} = Cl {b2} )
proof end;
end;

:: deftheorem Def14 defines anti-discrete TEX_4:def 14 :
for b1 being non empty TopSpace
for b2 being Subset of b1 holds
( b2 is anti-discrete iff for b3, b4 being Point of b1 st b3 in b2 & b4 in b2 holds
Cl {b3} = Cl {b4} );

theorem Th44: :: TEX_4:44
for b1 being non empty TopSpace
for b2 being Point of b1
for b3 being Subset of b1 st b3 is anti-discrete & Cl {b2} c= b3 holds
b3 = Cl {b2}
proof end;

theorem Th45: :: TEX_4:45
for b1 being non empty TopSpace
for b2 being Subset of b1 holds
( ( b2 is anti-discrete & b2 is closed ) iff for b3 being Point of b1 st b3 in b2 holds
b2 = Cl {b3} )
proof end;

theorem Th46: :: TEX_4:46
for b1 being non empty TopSpace
for b2 being Subset of b1 st b2 is anti-discrete & not b2 is open holds
b2 is boundary
proof end;

theorem Th47: :: TEX_4:47
for b1 being non empty TopSpace
for b2 being Point of b1 st Cl {b2} = {b2} holds
{b2} is maximal_anti-discrete
proof end;

theorem Th48: :: TEX_4:48
for b1 being non empty TopSpace
for b2 being Point of b1 holds MaxADSet b2 c= meet { b3 where B is Subset of b1 : ( b3 is open & b2 in b3 ) }
proof end;

theorem Th49: :: TEX_4:49
for b1 being non empty TopSpace
for b2 being Point of b1 holds MaxADSet b2 c= meet { b3 where B is Subset of b1 : ( b3 is closed & b2 in b3 ) }
proof end;

theorem Th50: :: TEX_4:50
for b1 being non empty TopSpace
for b2 being Point of b1 holds MaxADSet b2 c= Cl {b2}
proof end;

Lemma49: for b1 being non empty TopSpace
for b2, b3 being Point of b1 st MaxADSet b2 = MaxADSet b3 holds
Cl {b2} = Cl {b3}
proof end;

theorem Th51: :: TEX_4:51
for b1 being non empty TopSpace
for b2, b3 being Point of b1 holds
( MaxADSet b2 = MaxADSet b3 iff Cl {b2} = Cl {b3} )
proof end;

theorem Th52: :: TEX_4:52
for b1 being non empty TopSpace
for b2, b3 being Point of b1 holds
( MaxADSet b2 misses MaxADSet b3 iff Cl {b2} <> Cl {b3} )
proof end;

definition
let c1 be non empty TopSpace;
let c2 be Point of c1;
redefine func MaxADSet as MaxADSet c2 -> non empty Subset of a1 equals :: TEX_4:def 15
(Cl {a2}) /\ (meet { b1 where B is Subset of a1 : ( b1 is open & a2 in b1 ) } );
compatibility
for b1 being non empty Subset of c1 holds
( b1 = MaxADSet c2 iff b1 = (Cl {c2}) /\ (meet { b2 where B is Subset of c1 : ( b2 is open & c2 in b2 ) } ) )
proof end;
coherence
MaxADSet c2 is non empty Subset of c1
;
end;

:: deftheorem Def15 defines MaxADSet TEX_4:def 15 :
for b1 being non empty TopSpace
for b2 being Point of b1 holds MaxADSet b2 = (Cl {b2}) /\ (meet { b3 where B is Subset of b1 : ( b3 is open & b2 in b3 ) } );

theorem Th53: :: TEX_4:53
for b1 being non empty TopSpace
for b2, b3 being Point of b1 holds
( Cl {b2} c= Cl {b3} iff meet { b4 where B is Subset of b1 : ( b4 is open & b3 in b4 ) } c= meet { b4 where B is Subset of b1 : ( b4 is open & b2 in b4 ) } )
proof end;

theorem Th54: :: TEX_4:54
for b1 being non empty TopSpace
for b2, b3 being Point of b1 holds
( Cl {b2} c= Cl {b3} iff MaxADSet b3 c= meet { b4 where B is Subset of b1 : ( b4 is open & b2 in b4 ) } )
proof end;

theorem Th55: :: TEX_4:55
for b1 being non empty TopSpace
for b2, b3 being Point of b1 holds
( MaxADSet b2 misses MaxADSet b3 iff ( ex b4 being Subset of b1 st
( b4 is open & MaxADSet b2 c= b4 & b4 misses MaxADSet b3 ) or ex b4 being Subset of b1 st
( b4 is open & b4 misses MaxADSet b2 & MaxADSet b3 c= b4 ) ) )
proof end;

theorem Th56: :: TEX_4:56
for b1 being non empty TopSpace
for b2, b3 being Point of b1 holds
( MaxADSet b2 misses MaxADSet b3 iff ( ex b4 being Subset of b1 st
( b4 is closed & MaxADSet b2 c= b4 & b4 misses MaxADSet b3 ) or ex b4 being Subset of b1 st
( b4 is closed & b4 misses MaxADSet b2 & MaxADSet b3 c= b4 ) ) )
proof end;

theorem Th57: :: TEX_4:57
for b1 being non empty TopSpace
for b2 being Subset of b1 holds MaxADSet b2 c= meet { b3 where B is Subset of b1 : ( b3 is open & b2 c= b3 ) }
proof end;

theorem Th58: :: TEX_4:58
for b1 being non empty TopSpace
for b2 being Subset of b1 st b2 is open holds
MaxADSet b2 = b2
proof end;

theorem Th59: :: TEX_4:59
for b1 being non empty TopSpace
for b2 being Subset of b1 holds MaxADSet (Int b2) = Int b2 by Th58;

theorem Th60: :: TEX_4:60
for b1 being non empty TopSpace
for b2 being Subset of b1 holds MaxADSet b2 c= meet { b3 where B is Subset of b1 : ( b3 is closed & b2 c= b3 ) }
proof end;

theorem Th61: :: TEX_4:61
for b1 being non empty TopSpace
for b2 being Subset of b1 holds MaxADSet b2 c= Cl b2
proof end;

theorem Th62: :: TEX_4:62
for b1 being non empty TopSpace
for b2 being Subset of b1 st b2 is closed holds
MaxADSet b2 = b2
proof end;

theorem Th63: :: TEX_4:63
for b1 being non empty TopSpace
for b2 being Subset of b1 holds MaxADSet (Cl b2) = Cl b2 by Th62;

theorem Th64: :: TEX_4:64
for b1 being non empty TopSpace
for b2 being Subset of b1 holds Cl (MaxADSet b2) = Cl b2
proof end;

theorem Th65: :: TEX_4:65
for b1 being non empty TopSpace
for b2, b3 being Subset of b1 st MaxADSet b2 = MaxADSet b3 holds
Cl b2 = Cl b3
proof end;

theorem Th66: :: TEX_4:66
for b1 being non empty TopSpace
for b2, b3 being Subset of b1 st ( b2 is closed or b3 is closed ) holds
MaxADSet (b2 /\ b3) = (MaxADSet b2) /\ (MaxADSet b3)
proof end;

theorem Th67: :: TEX_4:67
for b1 being non empty TopSpace
for b2, b3 being Subset of b1 st ( b2 is open or b3 is open ) holds
MaxADSet (b2 /\ b3) = (MaxADSet b2) /\ (MaxADSet b3)
proof end;

theorem Th68: :: TEX_4:68
for b1 being non empty TopStruct
for b2 being SubSpace of b1
for b3 being Subset of b1 st b3 = the carrier of b2 & b2 is anti-discrete holds
b3 is anti-discrete
proof end;

theorem Th69: :: TEX_4:69
for b1 being non empty TopStruct
for b2 being SubSpace of b1 st b2 is TopSpace-like holds
for b3 being Subset of b1 st b3 = the carrier of b2 & b3 is anti-discrete holds
b2 is anti-discrete
proof end;

theorem Th70: :: TEX_4:70
for b1 being non empty TopSpace
for b2 being non empty SubSpace of b1 st ( for b3 being open SubSpace of b1 holds
( b2 misses b3 or b2 is SubSpace of b3 ) ) holds
b2 is anti-discrete
proof end;

theorem Th71: :: TEX_4:71
for b1 being non empty TopSpace
for b2 being non empty SubSpace of b1 st ( for b3 being closed SubSpace of b1 holds
( b2 misses b3 or b2 is SubSpace of b3 ) ) holds
b2 is anti-discrete
proof end;

theorem Th72: :: TEX_4:72
for b1 being non empty TopSpace
for b2 being anti-discrete SubSpace of b1
for b3 being open SubSpace of b1 holds
( b2 misses b3 or b2 is SubSpace of b3 )
proof end;

theorem Th73: :: TEX_4:73
for b1 being non empty TopSpace
for b2 being anti-discrete SubSpace of b1
for b3 being closed SubSpace of b1 holds
( b2 misses b3 or b2 is SubSpace of b3 )
proof end;

definition
let c1 be non empty TopStruct ;
let c2 be SubSpace of c1;
attr a2 is maximal_anti-discrete means :Def16: :: TEX_4:def 16
( a2 is anti-discrete & ( for b1 being SubSpace of a1 st b1 is anti-discrete & the carrier of a2 c= the carrier of b1 holds
the carrier of a2 = the carrier of b1 ) );
end;

:: deftheorem Def16 defines maximal_anti-discrete TEX_4:def 16 :
for b1 being non empty TopStruct
for b2 being SubSpace of b1 holds
( b2 is maximal_anti-discrete iff ( b2 is anti-discrete & ( for b3 being SubSpace of b1 st b3 is anti-discrete & the carrier of b2 c= the carrier of b3 holds
the carrier of b2 = the carrier of b3 ) ) );

registration
let c1 be non empty TopStruct ;
cluster maximal_anti-discrete -> anti-discrete SubSpace of a1;
coherence
for b1 being SubSpace of c1 st b1 is maximal_anti-discrete holds
b1 is anti-discrete
by Def16;
cluster non anti-discrete -> non maximal_anti-discrete SubSpace of a1;
coherence
for b1 being SubSpace of c1 st not b1 is anti-discrete holds
not b1 is maximal_anti-discrete
by Def16;
end;

theorem Th74: :: TEX_4:74
for b1 being non empty TopSpace
for b2 being non empty SubSpace of b1
for b3 being Subset of b1 st b3 = the carrier of b2 holds
( b2 is maximal_anti-discrete iff b3 is maximal_anti-discrete )
proof end;

registration
let c1 be non empty TopSpace;
cluster non empty open anti-discrete -> non empty anti-discrete maximal_anti-discrete SubSpace of a1;
coherence
for b1 being non empty SubSpace of c1 st b1 is open & b1 is anti-discrete holds
b1 is maximal_anti-discrete
proof end;
cluster non empty open non maximal_anti-discrete -> non empty non anti-discrete non maximal_anti-discrete SubSpace of a1;
coherence
for b1 being non empty SubSpace of c1 st b1 is open & not b1 is maximal_anti-discrete holds
not b1 is anti-discrete
proof end;
cluster non empty anti-discrete non maximal_anti-discrete -> non empty non open SubSpace of a1;
coherence
for b1 being non empty SubSpace of c1 st b1 is anti-discrete & not b1 is maximal_anti-discrete holds
not b1 is open
proof end;
cluster non empty closed anti-discrete -> non empty anti-discrete maximal_anti-discrete SubSpace of a1;
coherence
for b1 being non empty SubSpace of c1 st b1 is closed & b1 is anti-discrete holds
b1 is maximal_anti-discrete
proof end;
cluster non empty closed non maximal_anti-discrete -> non empty non anti-discrete non maximal_anti-discrete SubSpace of a1;
coherence
for b1 being non empty SubSpace of c1 st b1 is closed & not b1 is maximal_anti-discrete holds
not b1 is anti-discrete
proof end;
cluster non empty anti-discrete non maximal_anti-discrete -> non empty non closed SubSpace of a1;
coherence
for b1 being non empty SubSpace of c1 st b1 is anti-discrete & not b1 is maximal_anti-discrete holds
not b1 is closed
proof end;
end;

definition
let c1 be TopStruct ;
let c2 be Point of c1;
func MaxADSspace c2 -> strict SubSpace of a1 means :Def17: :: TEX_4:def 17
the carrier of a3 = MaxADSet a2;
existence
ex b1 being strict SubSpace of c1 st the carrier of b1 = MaxADSet c2
proof end;
uniqueness
for b1, b2 being strict SubSpace of c1 st the carrier of b1 = MaxADSet c2 & the carrier of b2 = MaxADSet c2 holds
b1 = b2
proof end;
end;

:: deftheorem Def17 defines MaxADSspace TEX_4:def 17 :
for b1 being TopStruct
for b2 being Point of b1
for b3 being strict SubSpace of b1 holds
( b3 = MaxADSspace b2 iff the carrier of b3 = MaxADSet b2 );

registration
let c1 be non empty TopStruct ;
let c2 be Point of c1;
cluster MaxADSspace a2 -> non empty strict ;
coherence
not MaxADSspace c2 is empty
proof end;
end;

Lemma63: for b1 being non empty TopStruct
for b2, b3 being SubSpace of b1 st the carrier of b2 c= the carrier of b3 holds
b2 is SubSpace of b3
proof end;

theorem Th75: :: TEX_4:75
for b1 being non empty TopStruct
for b2 being Point of b1 holds Sspace b2 is SubSpace of MaxADSspace b2
proof end;

theorem Th76: :: TEX_4:76
for b1 being non empty TopStruct
for b2, b3 being Point of b1 holds
( b3 is Point of (MaxADSspace b2) iff TopStruct(# the carrier of (MaxADSspace b3),the topology of (MaxADSspace b3) #) = TopStruct(# the carrier of (MaxADSspace b2),the topology of (MaxADSspace b2) #) )
proof end;

theorem Th77: :: TEX_4:77
for b1 being non empty TopStruct
for b2, b3 being Point of b1 holds
( the carrier of (MaxADSspace b2) misses the carrier of (MaxADSspace b3) or TopStruct(# the carrier of (MaxADSspace b2),the topology of (MaxADSspace b2) #) = TopStruct(# the carrier of (MaxADSspace b3),the topology of (MaxADSspace b3) #) )
proof end;

registration
let c1 be non empty TopSpace;
cluster strict anti-discrete maximal_anti-discrete SubSpace of a1;
existence
ex b1 being SubSpace of c1 st
( b1 is maximal_anti-discrete & b1 is strict )
proof end;
end;

registration
let c1 be non empty TopSpace;
let c2 be Point of c1;
cluster MaxADSspace a2 -> non empty strict anti-discrete maximal_anti-discrete ;
coherence
MaxADSspace c2 is maximal_anti-discrete
proof end;
end;

theorem Th78: :: TEX_4:78
for b1 being non empty TopSpace
for b2 being non empty closed SubSpace of b1
for b3 being Point of b1 st b3 is Point of b2 holds
MaxADSspace b3 is SubSpace of b2
proof end;

theorem Th79: :: TEX_4:79
for b1 being non empty TopSpace
for b2 being non empty open SubSpace of b1
for b3 being Point of b1 st b3 is Point of b2 holds
MaxADSspace b3 is SubSpace of b2
proof end;

theorem Th80: :: TEX_4:80
for b1 being non empty TopSpace
for b2 being Point of b1 st Cl {b2} = {b2} holds
Sspace b2 is maximal_anti-discrete
proof end;

definition
let c1 be TopStruct ;
let c2 be Subset of c1;
func Sspace c2 -> strict SubSpace of a1 means :Def18: :: TEX_4:def 18
the carrier of a3 = a2;
existence
ex b1 being strict SubSpace of c1 st the carrier of b1 = c2
proof end;
uniqueness
for b1, b2 being strict SubSpace of c1 st the carrier of b1 = c2 & the carrier of b2 = c2 holds
b1 = b2
proof end;
end;

:: deftheorem Def18 defines Sspace TEX_4:def 18 :
for b1 being TopStruct
for b2 being Subset of b1
for b3 being strict SubSpace of b1 holds
( b3 = Sspace b2 iff the carrier of b3 = b2 );

registration
let c1 be non empty TopStruct ;
let c2 be non empty Subset of c1;
cluster Sspace a2 -> non empty strict ;
coherence
not Sspace c2 is empty
proof end;
end;

theorem Th81: :: TEX_4:81
for b1 being non empty TopStruct
for b2 being non empty Subset of b1 holds b2 is Subset of (Sspace b2)
proof end;

theorem Th82: :: TEX_4:82
for b1 being non empty TopStruct
for b2 being SubSpace of b1
for b3 being non empty Subset of b1 st b3 is Subset of b2 holds
Sspace b3 is SubSpace of b2
proof end;

registration
let c1 be non empty non trivial TopStruct ;
cluster strict non proper SubSpace of a1;
existence
ex b1 being SubSpace of c1 st
( not b1 is proper & b1 is strict )
proof end;
end;

registration
let c1 be non empty non trivial TopStruct ;
let c2 be non empty non trivial Subset of c1;
cluster Sspace a2 -> non empty non trivial strict ;
coherence
not Sspace c2 is trivial
proof end;
end;

registration
let c1 be non empty TopStruct ;
let c2 be non empty non proper Subset of c1;
cluster Sspace a2 -> non empty strict non proper ;
coherence
not Sspace c2 is proper
proof end;
end;

definition
let c1 be non empty TopStruct ;
let c2 be Subset of c1;
func MaxADSspace c2 -> strict SubSpace of a1 means :Def19: :: TEX_4:def 19
the carrier of a3 = MaxADSet a2;
existence
ex b1 being strict SubSpace of c1 st the carrier of b1 = MaxADSet c2
proof end;
uniqueness
for b1, b2 being strict SubSpace of c1 st the carrier of b1 = MaxADSet c2 & the carrier of b2 = MaxADSet c2 holds
b1 = b2
proof end;
end;

:: deftheorem Def19 defines MaxADSspace TEX_4:def 19 :
for b1 being non empty TopStruct
for b2 being Subset of b1
for b3 being strict SubSpace of b1 holds
( b3 = MaxADSspace b2 iff the carrier of b3 = MaxADSet b2 );

registration
let c1 be non empty TopStruct ;
let c2 be non empty Subset of c1;
cluster MaxADSspace a2 -> non empty strict ;
coherence
not MaxADSspace c2 is empty
proof end;
end;

theorem Th83: :: TEX_4:83
for b1 being non empty TopStruct
for b2 being non empty Subset of b1 holds b2 is Subset of (MaxADSspace b2)
proof end;

theorem Th84: :: TEX_4:84
for b1 being non empty TopStruct
for b2 being non empty Subset of b1 holds Sspace b2 is SubSpace of MaxADSspace b2
proof end;

theorem Th85: :: TEX_4:85
for b1 being non empty TopStruct
for b2 being Point of b1 holds TopStruct(# the carrier of (MaxADSspace b2),the topology of (MaxADSspace b2) #) = TopStruct(# the carrier of (MaxADSspace {b2}),the topology of (MaxADSspace {b2}) #)
proof end;

theorem Th86: :: TEX_4:86
for b1 being non empty TopStruct
for b2, b3 being non empty Subset of b1 st b2 c= b3 holds
MaxADSspace b2 is SubSpace of MaxADSspace b3
proof end;

theorem Th87: :: TEX_4:87
for b1 being non empty TopStruct
for b2 being non empty Subset of b1 holds TopStruct(# the carrier of (MaxADSspace b2),the topology of (MaxADSspace b2) #) = TopStruct(# the carrier of (MaxADSspace (MaxADSet b2)),the topology of (MaxADSspace (MaxADSet b2)) #)
proof end;

theorem Th88: :: TEX_4:88
for b1 being non empty TopStruct
for b2, b3 being non empty Subset of b1 st b2 is Subset of (MaxADSspace b3) holds
MaxADSspace b2 is SubSpace of MaxADSspace b3
proof end;

theorem Th89: :: TEX_4:89
for b1 being non empty TopStruct
for b2, b3 being non empty Subset of b1 holds
( ( b3 is Subset of (MaxADSspace b2) & b2 is Subset of (MaxADSspace b3) ) iff TopStruct(# the carrier of (MaxADSspace b2),the topology of (MaxADSspace b2) #) = TopStruct(# the carrier of (MaxADSspace b3),the topology of (MaxADSspace b3) #) )
proof end;

registration
let c1 be non empty non trivial TopStruct ;
let c2 be non empty non trivial Subset of c1;
cluster MaxADSspace a2 -> non empty non trivial strict ;
coherence
not MaxADSspace c2 is trivial
proof end;
end;

registration
let c1 be non empty TopStruct ;
let c2 be non empty non proper Subset of c1;
cluster MaxADSspace a2 -> non empty strict non proper ;
coherence
not MaxADSspace c2 is proper
proof end;
end;

theorem Th90: :: TEX_4:90
for b1 being non empty TopSpace
for b2 being open SubSpace of b1
for b3 being non empty Subset of b1 st b3 is Subset of b2 holds
MaxADSspace b3 is SubSpace of b2
proof end;

theorem Th91: :: TEX_4:91
for b1 being non empty TopSpace
for b2 being closed SubSpace of b1
for b3 being non empty Subset of b1 st b3 is Subset of b2 holds
MaxADSspace b3 is SubSpace of b2
proof end;