:: WAYBEL_9 semantic presentation

registration
let c1 be non empty RelStr ;
cluster id a1 -> monotone ;
coherence
id c1 is monotone
by YELLOW_2:13;
end;

definition
let c1, c2 be non empty RelStr ;
let c3 be Function of c1,c2;
redefine attr a3 is antitone means :Def1: :: WAYBEL_9:def 1
for b1, b2 being Element of a1 st b1 <= b2 holds
a3 . b1 >= a3 . b2;
compatibility
( c3 is antitone iff for b1, b2 being Element of c1 st b1 <= b2 holds
c3 . b1 >= c3 . b2 )
proof end;
end;

:: deftheorem Def1 defines antitone WAYBEL_9:def 1 :
for b1, b2 being non empty RelStr
for b3 being Function of b1,b2 holds
( b3 is antitone iff for b4, b5 being Element of b1 st b4 <= b5 holds
b3 . b4 >= b3 . b5 );

theorem Th1: :: WAYBEL_9:1
for b1, b2 being RelStr
for b3, b4 being non empty RelStr
for b5 being Function of b1,b2
for b6 being Function of b3,b4 st RelStr(# the carrier of b1,the InternalRel of b1 #) = RelStr(# the carrier of b3,the InternalRel of b3 #) & RelStr(# the carrier of b2,the InternalRel of b2 #) = RelStr(# the carrier of b4,the InternalRel of b4 #) & b5 = b6 & b5 is monotone holds
b6 is monotone
proof end;

theorem Th2: :: WAYBEL_9:2
for b1, b2 being RelStr
for b3, b4 being non empty RelStr
for b5 being Function of b1,b2
for b6 being Function of b3,b4 st RelStr(# the carrier of b1,the InternalRel of b1 #) = RelStr(# the carrier of b3,the InternalRel of b3 #) & RelStr(# the carrier of b2,the InternalRel of b2 #) = RelStr(# the carrier of b4,the InternalRel of b4 #) & b5 = b6 & b5 is antitone holds
b6 is antitone
proof end;

theorem Th3: :: WAYBEL_9:3
for b1, b2 being 1-sorted
for b3 being Subset-Family of b1
for b4 being Subset-Family of b2 st the carrier of b1 = the carrier of b2 & b3 = b4 & b3 is_a_cover_of b1 holds
b4 is_a_cover_of b2
proof end;

Lemma5: for b1 being reflexive antisymmetric with_infima RelStr
for b2 being Element of b1 holds uparrow b2 = { b3 where B is Element of b1 : b3 "/\" b2 = b2 }
proof end;

theorem Th4: :: WAYBEL_9:4
for b1 being reflexive antisymmetric with_suprema RelStr
for b2 being Element of b1 holds uparrow b2 = {b2} "\/" ([#] b1)
proof end;

Lemma7: for b1 being reflexive antisymmetric with_suprema RelStr
for b2 being Element of b1 holds downarrow b2 = { b3 where B is Element of b1 : b3 "\/" b2 = b2 }
proof end;

theorem Th5: :: WAYBEL_9:5
for b1 being reflexive antisymmetric with_infima RelStr
for b2 being Element of b1 holds downarrow b2 = {b2} "/\" ([#] b1)
proof end;

theorem Th6: :: WAYBEL_9:6
for b1 being reflexive antisymmetric with_infima RelStr
for b2 being Element of b1 holds (b2 "/\" ) .: (uparrow b2) = {b2}
proof end;

theorem Th7: :: WAYBEL_9:7
for b1 being reflexive antisymmetric with_infima RelStr
for b2 being Element of b1 holds (b2 "/\" ) " {b2} = uparrow b2
proof end;

theorem Th8: :: WAYBEL_9:8
for b1 being non empty 1-sorted
for b2 being non empty NetStr of b1 holds b2 is_eventually_in rng the mapping of b2
proof end;

Lemma11: for b1 being non empty reflexive transitive RelStr
for b2 being non empty directed Subset of b1
for b3 being Function of b2,the carrier of b1 holds NetStr(# b2,(the InternalRel of b1 |_2 b2),b3 #) is net of b1
proof end;

registration
let c1 be non empty reflexive RelStr ;
let c2 be non empty directed Subset of c1;
let c3 be Function of c2,the carrier of c1;
cluster NetStr(# a2,(the InternalRel of a1 |_2 a2),a3 #) -> directed ;
coherence
NetStr(# c2,(the InternalRel of c1 |_2 c2),c3 #) is directed
by WAYBEL_2:19;
end;

registration
let c1 be non empty reflexive transitive RelStr ;
let c2 be non empty directed Subset of c1;
let c3 be Function of c2,the carrier of c1;
cluster NetStr(# a2,(the InternalRel of a1 |_2 a2),a3 #) -> transitive directed ;
coherence
NetStr(# c2,(the InternalRel of c1 |_2 c2),c3 #) is transitive
by Lemma11;
end;

theorem Th9: :: WAYBEL_9:9
for b1 being non empty reflexive transitive RelStr st ( for b2 being Element of b1
for b3 being net of b1 st b3 is eventually-directed holds
b2 "/\" (sup b3) = sup ({b2} "/\" (rng (netmap b3,b1))) ) holds
b1 is satisfying_MC
proof end;

theorem Th10: :: WAYBEL_9:10
for b1 being non empty RelStr
for b2 being Element of b1
for b3 being net of b1 holds b2 "/\" b3 is net of b1
proof end;

definition
let c1 be non empty RelStr ;
let c2 be Element of c1;
let c3 be net of c1;
redefine func "/\" as c2 "/\" c3 -> strict net of a1;
coherence
c2 "/\" c3 is strict net of c1
by Th10;
end;

registration
let c1 be non empty RelStr ;
let c2 be Element of c1;
let c3 be non empty reflexive NetStr of c1;
cluster a2 "/\" a3 -> reflexive ;
coherence
c2 "/\" c3 is reflexive
proof end;
end;

registration
let c1 be non empty RelStr ;
let c2 be Element of c1;
let c3 be non empty antisymmetric NetStr of c1;
cluster a2 "/\" a3 -> antisymmetric ;
coherence
c2 "/\" c3 is antisymmetric
proof end;
end;

registration
let c1 be non empty RelStr ;
let c2 be Element of c1;
let c3 be non empty transitive NetStr of c1;
cluster a2 "/\" a3 -> transitive ;
coherence
c2 "/\" c3 is transitive
proof end;
end;

registration
let c1 be non empty RelStr ;
let c2 be set ;
let c3 be Function of c2,the carrier of c1;
cluster FinSups a3 -> transitive ;
coherence
FinSups c3 is transitive
proof end;
end;

definition
let c1 be non empty RelStr ;
let c2 be NetStr of c1;
func inf c2 -> Element of a1 equals :: WAYBEL_9:def 2
Inf ;
coherence
Inf is Element of c1
;
end;

:: deftheorem Def2 defines inf WAYBEL_9:def 2 :
for b1 being non empty RelStr
for b2 being NetStr of b1 holds inf b2 = Inf ;

definition
let c1 be RelStr ;
let c2 be NetStr of c1;
pred ex_sup_of c2 means :Def3: :: WAYBEL_9:def 3
ex_sup_of rng the mapping of a2,a1;
pred ex_inf_of c2 means :Def4: :: WAYBEL_9:def 4
ex_inf_of rng the mapping of a2,a1;
end;

:: deftheorem Def3 defines ex_sup_of WAYBEL_9:def 3 :
for b1 being RelStr
for b2 being NetStr of b1 holds
( ex_sup_of b2 iff ex_sup_of rng the mapping of b2,b1 );

:: deftheorem Def4 defines ex_inf_of WAYBEL_9:def 4 :
for b1 being RelStr
for b2 being NetStr of b1 holds
( ex_inf_of b2 iff ex_inf_of rng the mapping of b2,b1 );

definition
let c1 be RelStr ;
func c1 +id -> strict NetStr of a1 means :Def5: :: WAYBEL_9:def 5
( RelStr(# the carrier of a2,the InternalRel of a2 #) = RelStr(# the carrier of a1,the InternalRel of a1 #) & the mapping of a2 = id a1 );
existence
ex b1 being strict NetStr of c1 st
( RelStr(# the carrier of b1,the InternalRel of b1 #) = RelStr(# the carrier of c1,the InternalRel of c1 #) & the mapping of b1 = id c1 )
proof end;
uniqueness
for b1, b2 being strict NetStr of c1 st RelStr(# the carrier of b1,the InternalRel of b1 #) = RelStr(# the carrier of c1,the InternalRel of c1 #) & the mapping of b1 = id c1 & RelStr(# the carrier of b2,the InternalRel of b2 #) = RelStr(# the carrier of c1,the InternalRel of c1 #) & the mapping of b2 = id c1 holds
b1 = b2
;
end;

:: deftheorem Def5 defines +id WAYBEL_9:def 5 :
for b1 being RelStr
for b2 being strict NetStr of b1 holds
( b2 = b1 +id iff ( RelStr(# the carrier of b2,the InternalRel of b2 #) = RelStr(# the carrier of b1,the InternalRel of b1 #) & the mapping of b2 = id b1 ) );

registration
let c1 be non empty RelStr ;
cluster a1 +id -> non empty strict ;
coherence
not c1 +id is empty
proof end;
end;

registration
let c1 be reflexive RelStr ;
cluster a1 +id -> reflexive strict ;
coherence
c1 +id is reflexive
proof end;
end;

registration
let c1 be antisymmetric RelStr ;
cluster a1 +id -> antisymmetric strict ;
coherence
c1 +id is antisymmetric
proof end;
end;

registration
let c1 be transitive RelStr ;
cluster a1 +id -> transitive strict ;
coherence
c1 +id is transitive
proof end;
end;

registration
let c1 be with_suprema RelStr ;
cluster a1 +id -> non empty strict directed ;
coherence
c1 +id is directed
proof end;
end;

registration
let c1 be directed RelStr ;
cluster a1 +id -> strict directed ;
coherence
c1 +id is directed
proof end;
end;

registration
let c1 be non empty RelStr ;
cluster a1 +id -> non empty strict monotone eventually-directed ;
coherence
( c1 +id is monotone & c1 +id is eventually-directed )
proof end;
end;

definition
let c1 be RelStr ;
func c1 opp+id -> strict NetStr of a1 means :Def6: :: WAYBEL_9:def 6
( the carrier of a2 = the carrier of a1 & the InternalRel of a2 = the InternalRel of a1 ~ & the mapping of a2 = id a1 );
existence
ex b1 being strict NetStr of c1 st
( the carrier of b1 = the carrier of c1 & the InternalRel of b1 = the InternalRel of c1 ~ & the mapping of b1 = id c1 )
proof end;
uniqueness
for b1, b2 being strict NetStr of c1 st the carrier of b1 = the carrier of c1 & the InternalRel of b1 = the InternalRel of c1 ~ & the mapping of b1 = id c1 & the carrier of b2 = the carrier of c1 & the InternalRel of b2 = the InternalRel of c1 ~ & the mapping of b2 = id c1 holds
b1 = b2
;
end;

:: deftheorem Def6 defines opp+id WAYBEL_9:def 6 :
for b1 being RelStr
for b2 being strict NetStr of b1 holds
( b2 = b1 opp+id iff ( the carrier of b2 = the carrier of b1 & the InternalRel of b2 = the InternalRel of b1 ~ & the mapping of b2 = id b1 ) );

theorem Th11: :: WAYBEL_9:11
for b1 being RelStr holds RelStr(# the carrier of (b1 ~ ),the InternalRel of (b1 ~ ) #) = RelStr(# the carrier of (b1 opp+id ),the InternalRel of (b1 opp+id ) #)
proof end;

registration
let c1 be non empty RelStr ;
cluster a1 opp+id -> non empty strict ;
coherence
not c1 opp+id is empty
proof end;
end;

registration
let c1 be reflexive RelStr ;
cluster a1 opp+id -> reflexive strict ;
coherence
c1 opp+id is reflexive
proof end;
end;

registration
let c1 be antisymmetric RelStr ;
cluster a1 opp+id -> antisymmetric strict ;
coherence
c1 opp+id is antisymmetric
proof end;
end;

registration
let c1 be transitive RelStr ;
cluster a1 opp+id -> transitive strict ;
coherence
c1 opp+id is transitive
proof end;
end;

registration
let c1 be with_infima RelStr ;
cluster a1 opp+id -> non empty strict directed ;
coherence
c1 opp+id is directed
proof end;
end;

registration
let c1 be non empty RelStr ;
cluster a1 opp+id -> non empty strict antitone eventually-filtered ;
coherence
( c1 opp+id is antitone & c1 opp+id is eventually-filtered )
proof end;
end;

definition
let c1 be non empty 1-sorted ;
let c2 be non empty NetStr of c1;
let c3 be Element of c2;
func c2 | c3 -> strict NetStr of a1 means :Def7: :: WAYBEL_9:def 7
( ( for b1 being set holds
( b1 in the carrier of a4 iff ex b2 being Element of a2 st
( b2 = b1 & a3 <= b2 ) ) ) & the InternalRel of a4 = the InternalRel of a2 |_2 the carrier of a4 & the mapping of a4 = the mapping of a2 | the carrier of a4 );
existence
ex b1 being strict NetStr of c1 st
( ( for b2 being set holds
( b2 in the carrier of b1 iff ex b3 being Element of c2 st
( b3 = b2 & c3 <= b3 ) ) ) & the InternalRel of b1 = the InternalRel of c2 |_2 the carrier of b1 & the mapping of b1 = the mapping of c2 | the carrier of b1 )
proof end;
uniqueness
for b1, b2 being strict NetStr of c1 st ( for b3 being set holds
( b3 in the carrier of b1 iff ex b4 being Element of c2 st
( b4 = b3 & c3 <= b4 ) ) ) & the InternalRel of b1 = the InternalRel of c2 |_2 the carrier of b1 & the mapping of b1 = the mapping of c2 | the carrier of b1 & ( for b3 being set holds
( b3 in the carrier of b2 iff ex b4 being Element of c2 st
( b4 = b3 & c3 <= b4 ) ) ) & the InternalRel of b2 = the InternalRel of c2 |_2 the carrier of b2 & the mapping of b2 = the mapping of c2 | the carrier of b2 holds
b1 = b2
proof end;
end;

:: deftheorem Def7 defines | WAYBEL_9:def 7 :
for b1 being non empty 1-sorted
for b2 being non empty NetStr of b1
for b3 being Element of b2
for b4 being strict NetStr of b1 holds
( b4 = b2 | b3 iff ( ( for b5 being set holds
( b5 in the carrier of b4 iff ex b6 being Element of b2 st
( b6 = b5 & b3 <= b6 ) ) ) & the InternalRel of b4 = the InternalRel of b2 |_2 the carrier of b4 & the mapping of b4 = the mapping of b2 | the carrier of b4 ) );

theorem Th12: :: WAYBEL_9:12
for b1 being non empty 1-sorted
for b2 being non empty NetStr of b1
for b3 being Element of b2 holds the carrier of (b2 | b3) = { b4 where B is Element of b2 : b3 <= b4 }
proof end;

theorem Th13: :: WAYBEL_9:13
for b1 being non empty 1-sorted
for b2 being non empty NetStr of b1
for b3 being Element of b2 holds the carrier of (b2 | b3) c= the carrier of b2
proof end;

theorem Th14: :: WAYBEL_9:14
for b1 being non empty 1-sorted
for b2 being non empty NetStr of b1
for b3 being Element of b2 holds b2 | b3 is full SubNetStr of b2
proof end;

registration
let c1 be non empty 1-sorted ;
let c2 be non empty reflexive NetStr of c1;
let c3 be Element of c2;
cluster a2 | a3 -> non empty reflexive strict ;
coherence
( not c2 | c3 is empty & c2 | c3 is reflexive )
proof end;
end;

registration
let c1 be non empty 1-sorted ;
let c2 be non empty directed NetStr of c1;
let c3 be Element of c2;
cluster a2 | a3 -> non empty strict ;
coherence
not c2 | c3 is empty
proof end;
end;

registration
let c1 be non empty 1-sorted ;
let c2 be non empty reflexive antisymmetric NetStr of c1;
let c3 be Element of c2;
cluster a2 | a3 -> non empty reflexive antisymmetric strict ;
coherence
c2 | c3 is antisymmetric
proof end;
end;

registration
let c1 be non empty 1-sorted ;
let c2 be non empty antisymmetric directed NetStr of c1;
let c3 be Element of c2;
cluster a2 | a3 -> non empty antisymmetric strict ;
coherence
c2 | c3 is antisymmetric
proof end;
end;

registration
let c1 be non empty 1-sorted ;
let c2 be non empty reflexive transitive NetStr of c1;
let c3 be Element of c2;
cluster a2 | a3 -> non empty reflexive transitive strict ;
coherence
c2 | c3 is transitive
proof end;
end;

registration
let c1 be non empty 1-sorted ;
let c2 be net of c1;
let c3 be Element of c2;
cluster a2 | a3 -> non empty transitive strict directed ;
coherence
( c2 | c3 is transitive & c2 | c3 is directed )
proof end;
end;

theorem Th15: :: WAYBEL_9:15
for b1 being non empty 1-sorted
for b2 being non empty reflexive NetStr of b1
for b3, b4 being Element of b2
for b5 being Element of (b2 | b3) st b4 = b5 holds
b2 . b4 = (b2 | b3) . b5
proof end;

theorem Th16: :: WAYBEL_9:16
for b1 being non empty 1-sorted
for b2 being non empty directed NetStr of b1
for b3, b4 being Element of b2
for b5 being Element of (b2 | b3) st b4 = b5 holds
b2 . b4 = (b2 | b3) . b5
proof end;

theorem Th17: :: WAYBEL_9:17
for b1 being non empty 1-sorted
for b2 being net of b1
for b3 being Element of b2 holds b2 | b3 is subnet of b2
proof end;

registration
let c1 be non empty 1-sorted ;
let c2 be net of c1;
cluster strict subnet of a2;
existence
ex b1 being subnet of c2 st b1 is strict
proof end;
end;

definition
let c1 be non empty 1-sorted ;
let c2 be net of c1;
let c3 be Element of c2;
redefine func | as c2 | c3 -> strict subnet of a2;
coherence
c2 | c3 is strict subnet of c2
by Th17;
end;

definition
let c1 be non empty 1-sorted ;
let c2 be 1-sorted ;
let c3 be Function of c1,c2;
let c4 be NetStr of c1;
func c3 * c4 -> strict NetStr of a2 means :Def8: :: WAYBEL_9:def 8
( RelStr(# the carrier of a5,the InternalRel of a5 #) = RelStr(# the carrier of a4,the InternalRel of a4 #) & the mapping of a5 = a3 * the mapping of a4 );
existence
ex b1 being strict NetStr of c2 st
( RelStr(# the carrier of b1,the InternalRel of b1 #) = RelStr(# the carrier of c4,the InternalRel of c4 #) & the mapping of b1 = c3 * the mapping of c4 )
proof end;
uniqueness
for b1, b2 being strict NetStr of c2 st RelStr(# the carrier of b1,the InternalRel of b1 #) = RelStr(# the carrier of c4,the InternalRel of c4 #) & the mapping of b1 = c3 * the mapping of c4 & RelStr(# the carrier of b2,the InternalRel of b2 #) = RelStr(# the carrier of c4,the InternalRel of c4 #) & the mapping of b2 = c3 * the mapping of c4 holds
b1 = b2
;
end;

:: deftheorem Def8 defines * WAYBEL_9:def 8 :
for b1 being non empty 1-sorted
for b2 being 1-sorted
for b3 being Function of b1,b2
for b4 being NetStr of b1
for b5 being strict NetStr of b2 holds
( b5 = b3 * b4 iff ( RelStr(# the carrier of b5,the InternalRel of b5 #) = RelStr(# the carrier of b4,the InternalRel of b4 #) & the mapping of b5 = b3 * the mapping of b4 ) );

registration
let c1 be non empty 1-sorted ;
let c2 be 1-sorted ;
let c3 be Function of c1,c2;
let c4 be non empty NetStr of c1;
cluster a3 * a4 -> non empty strict ;
coherence
not c3 * c4 is empty
proof end;
end;

registration
let c1 be non empty 1-sorted ;
let c2 be 1-sorted ;
let c3 be Function of c1,c2;
let c4 be reflexive NetStr of c1;
cluster a3 * a4 -> reflexive strict ;
coherence
c3 * c4 is reflexive
proof end;
end;

registration
let c1 be non empty 1-sorted ;
let c2 be 1-sorted ;
let c3 be Function of c1,c2;
let c4 be antisymmetric NetStr of c1;
cluster a3 * a4 -> antisymmetric strict ;
coherence
c3 * c4 is antisymmetric
proof end;
end;

registration
let c1 be non empty 1-sorted ;
let c2 be 1-sorted ;
let c3 be Function of c1,c2;
let c4 be transitive NetStr of c1;
cluster a3 * a4 -> transitive strict ;
coherence
c3 * c4 is transitive
proof end;
end;

registration
let c1 be non empty 1-sorted ;
let c2 be 1-sorted ;
let c3 be Function of c1,c2;
let c4 be directed NetStr of c1;
cluster a3 * a4 -> strict directed ;
coherence
c3 * c4 is directed
proof end;
end;

theorem Th18: :: WAYBEL_9:18
for b1 being non empty RelStr
for b2 being non empty NetStr of b1
for b3 being Element of b1 holds (b3 "/\" ) * b2 = b3 "/\" b2
proof end;

theorem Th19: :: WAYBEL_9:19
for b1, b2 being TopStruct
for b3 being Subset-Family of b1
for b4 being Subset-Family 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 open holds
b4 is open
proof end;

theorem Th20: :: WAYBEL_9:20
for b1, b2 being TopStruct
for b3 being Subset-Family of b1
for b4 being Subset-Family 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 closed holds
b4 is closed
proof end;

definition
attr a1 is strict;
struct TopRelStr -> TopStruct , RelStr ;
aggr TopRelStr(# carrier, InternalRel, topology #) -> TopRelStr ;
end;

registration
let c1 be non empty set ;
let c2 be Relation of c1,c1;
let c3 be Subset-Family of c1;
cluster TopRelStr(# a1,a2,a3 #) -> non empty ;
coherence
not TopRelStr(# c1,c2,c3 #) is empty
proof end;
end;

registration
let c1 be set ;
let c2 be Relation of {c1};
let c3 be Subset-Family of {c1};
cluster TopRelStr(# {a1},a2,a3 #) -> non empty trivial ;
coherence
TopRelStr(# {c1},c2,c3 #) is trivial
proof end;
end;

registration
let c1 be set ;
let c2 be Order of c1;
let c3 be Subset-Family of c1;
cluster TopRelStr(# a1,a2,a3 #) -> reflexive transitive antisymmetric ;
coherence
( TopRelStr(# c1,c2,c3 #) is reflexive & TopRelStr(# c1,c2,c3 #) is transitive & TopRelStr(# c1,c2,c3 #) is antisymmetric )
proof end;
end;

Lemma27: for b1 being Subset-Family of {0}
for b2 being Relation of {0} st b1 = {{} ,{0}} & b2 = {[0,0]} holds
( TopRelStr(# {0},b2,b1 #) is trivial & TopRelStr(# {0},b2,b1 #) is reflexive & not TopRelStr(# {0},b2,b1 #) is empty & TopRelStr(# {0},b2,b1 #) is discrete & TopRelStr(# {0},b2,b1 #) is finite )
proof end;

registration
cluster non empty reflexive discrete finite trivial strict TopRelStr ;
existence
ex b1 being TopRelStr st
( b1 is trivial & b1 is reflexive & not b1 is empty & b1 is discrete & b1 is strict & b1 is finite )
proof end;
end;

definition
mode TopLattice is TopSpace-like reflexive transitive antisymmetric with_suprema with_infima TopRelStr ;
end;

registration
cluster non empty compact Hausdorff discrete finite trivial strict TopRelStr ;
existence
ex b1 being TopLattice st
( b1 is strict & not b1 is empty & b1 is trivial & b1 is discrete & b1 is finite & b1 is compact & b1 is being_T2 )
proof end;
end;

registration
let c1 be non empty Hausdorff TopSpace;
cluster non empty -> non empty Hausdorff SubSpace of a1;
coherence
for b1 being non empty SubSpace of c1 holds b1 is being_T2
by TOPMETR:3;
end;

theorem Th21: :: WAYBEL_9:21
for b1 being non empty TopSpace
for b2 being Point of b1
for b3 being Element of (OpenNeighborhoods b2) holds b3 is a_neighborhood of b2
proof end;

theorem Th22: :: WAYBEL_9:22
for b1 being non empty TopSpace
for b2 being Point of b1
for b3, b4 being Element of (OpenNeighborhoods b2) holds b3 /\ b4 is Element of (OpenNeighborhoods b2)
proof end;

theorem Th23: :: WAYBEL_9:23
for b1 being non empty TopSpace
for b2 being Point of b1
for b3, b4 being Element of (OpenNeighborhoods b2) holds b3 \/ b4 is Element of (OpenNeighborhoods b2)
proof end;

theorem Th24: :: WAYBEL_9:24
for b1 being non empty TopSpace
for b2 being Element of b1
for b3 being net of b1 st b2 in Lim b3 holds
for b4 being Subset of b1 st b4 = rng the mapping of b3 holds
b2 in Cl b4
proof end;

theorem Th25: :: WAYBEL_9:25
for b1 being Hausdorff TopLattice
for b2 being convergent net of b1
for b3 being Function of b1,b1 st b3 is continuous holds
b3 . (lim b2) in Lim (b3 * b2)
proof end;

theorem Th26: :: WAYBEL_9:26
for b1 being Hausdorff TopLattice
for b2 being convergent net of b1
for b3 being Element of b1 st b3 "/\" is continuous holds
b3 "/\" (lim b2) in Lim (b3 "/\" b2)
proof end;

theorem Th27: :: WAYBEL_9:27
for b1 being Hausdorff TopLattice
for b2 being Element of b1 st ( for b3 being Element of b1 holds b3 "/\" is continuous ) holds
uparrow b2 is closed
proof end;

theorem Th28: :: WAYBEL_9:28
for b1 being compact Hausdorff TopLattice
for b2 being Element of b1 st ( for b3 being Element of b1 holds b3 "/\" is continuous ) holds
downarrow b2 is closed
proof end;

definition
let c1 be non empty TopSpace;
let c2 be non empty NetStr of c1;
let c3 be Point of c1;
pred c3 is_a_cluster_point_of c2 means :Def9: :: WAYBEL_9:def 9
for b1 being a_neighborhood of a3 holds a2 is_often_in b1;
end;

:: deftheorem Def9 defines is_a_cluster_point_of WAYBEL_9:def 9 :
for b1 being non empty TopSpace
for b2 being non empty NetStr of b1
for b3 being Point of b1 holds
( b3 is_a_cluster_point_of b2 iff for b4 being a_neighborhood of b3 holds b2 is_often_in b4 );

theorem Th29: :: WAYBEL_9:29
for b1 being non empty TopSpace
for b2 being net of b1
for b3 being Point of b1 st b3 in Lim b2 holds
b3 is_a_cluster_point_of b2
proof end;

theorem Th30: :: WAYBEL_9:30
for b1 being non empty compact Hausdorff TopSpace
for b2 being net of b1 ex b3 being Point of b1 st b3 is_a_cluster_point_of b2
proof end;

theorem Th31: :: WAYBEL_9:31
for b1 being non empty TopSpace
for b2 being net of b1
for b3 being subnet of b2
for b4 being Point of b1 st b4 is_a_cluster_point_of b3 holds
b4 is_a_cluster_point_of b2
proof end;

theorem Th32: :: WAYBEL_9:32
for b1 being non empty TopSpace
for b2 being net of b1
for b3 being Point of b1 st b3 is_a_cluster_point_of b2 holds
ex b4 being subnet of b2 st b3 in Lim b4
proof end;

theorem Th33: :: WAYBEL_9:33
for b1 being non empty compact Hausdorff TopSpace
for b2 being net of b1 st ( for b3, b4 being Point of b1 st b3 is_a_cluster_point_of b2 & b4 is_a_cluster_point_of b2 holds
b3 = b4 ) holds
for b3 being Point of b1 st b3 is_a_cluster_point_of b2 holds
b3 in Lim b2
proof end;

theorem Th34: :: WAYBEL_9:34
for b1 being non empty TopSpace
for b2 being Point of b1
for b3 being net of b1
for b4 being Subset of b1 st b2 is_a_cluster_point_of b3 & b4 is closed & rng the mapping of b3 c= b4 holds
b2 in b4
proof end;

Lemma41: for b1 being compact Hausdorff TopLattice
for b2 being net of b1
for b3 being Point of b1
for b4 being Element of b1 st b3 = b4 & ( for b5 being Element of b1 holds b5 "/\" is continuous ) & b2 is eventually-directed & b3 is_a_cluster_point_of b2 holds
b4 is_>=_than rng the mapping of b2
proof end;

Lemma42: for b1 being compact Hausdorff TopLattice
for b2 being net of b1
for b3 being Point of b1
for b4 being Element of b1 st b3 = b4 & ( for b5 being Element of b1 holds b5 "/\" is continuous ) & b3 is_a_cluster_point_of b2 holds
for b5 being Element of b1 st rng the mapping of b2 is_<=_than b5 holds
b4 <= b5
proof end;

theorem Th35: :: WAYBEL_9:35
for b1 being compact Hausdorff TopLattice
for b2 being Point of b1
for b3 being net of b1 st ( for b4 being Element of b1 holds b4 "/\" is continuous ) & b3 is eventually-directed & b2 is_a_cluster_point_of b3 holds
b2 = sup b3
proof end;

Lemma44: for b1 being compact Hausdorff TopLattice
for b2 being net of b1
for b3 being Point of b1
for b4 being Element of b1 st b3 = b4 & ( for b5 being Element of b1 holds b5 "/\" is continuous ) & b2 is eventually-filtered & b3 is_a_cluster_point_of b2 holds
b4 is_<=_than rng the mapping of b2
proof end;

Lemma45: for b1 being compact Hausdorff TopLattice
for b2 being net of b1
for b3 being Point of b1
for b4 being Element of b1 st b3 = b4 & ( for b5 being Element of b1 holds b5 "/\" is continuous ) & b3 is_a_cluster_point_of b2 holds
for b5 being Element of b1 st rng the mapping of b2 is_>=_than b5 holds
b4 >= b5
proof end;

theorem Th36: :: WAYBEL_9:36
for b1 being compact Hausdorff TopLattice
for b2 being Point of b1
for b3 being net of b1 st ( for b4 being Element of b1 holds b4 "/\" is continuous ) & b3 is eventually-filtered & b2 is_a_cluster_point_of b3 holds
b2 = inf b3
proof end;

theorem Th37: :: WAYBEL_9:37
for b1 being Hausdorff TopLattice st ( for b2 being net of b1 st b2 is eventually-directed holds
( ex_sup_of b2 & sup b2 in Lim b2 ) ) & ( for b2 being Element of b1 holds b2 "/\" is continuous ) holds
b1 is meet-continuous
proof end;

theorem Th38: :: WAYBEL_9:38
for b1 being compact Hausdorff TopLattice st ( for b2 being Element of b1 holds b2 "/\" is continuous ) holds
for b2 being net of b1 st b2 is eventually-directed holds
( ex_sup_of b2 & sup b2 in Lim b2 )
proof end;

theorem Th39: :: WAYBEL_9:39
for b1 being compact Hausdorff TopLattice st ( for b2 being Element of b1 holds b2 "/\" is continuous ) holds
for b2 being net of b1 st b2 is eventually-filtered holds
( ex_inf_of b2 & inf b2 in Lim b2 )
proof end;

theorem Th40: :: WAYBEL_9:40
for b1 being compact Hausdorff TopLattice st ( for b2 being Element of b1 holds b2 "/\" is continuous ) holds
b1 is bounded
proof end;

theorem Th41: :: WAYBEL_9:41
for b1 being compact Hausdorff TopLattice st ( for b2 being Element of b1 holds b2 "/\" is continuous ) holds
b1 is meet-continuous
proof end;