let L be lower-bounded sup-Semilattice; :: thesis: (Rel2Map L) * (Map2Rel L) = id the carrier of (MonSet L)
set LS = (Rel2Map L) * (Map2Rel L);
set R = id the carrier of (MonSet L);
A1: dom ((Rel2Map L) * (Map2Rel L)) = the carrier of (MonSet L) by FUNCT_2:def 1;
A2: dom (id the carrier of (MonSet L)) = the carrier of (MonSet L) by FUNCT_1:34;
for a being set st a in the carrier of (MonSet L) holds
((Rel2Map L) * (Map2Rel L)) . a = (id the carrier of (MonSet L)) . a
proof
let a be set ; :: thesis: ( a in the carrier of (MonSet L) implies ((Rel2Map L) * (Map2Rel L)) . a = (id the carrier of (MonSet L)) . a )
assume A3: a in the carrier of (MonSet L) ; :: thesis: ((Rel2Map L) * (Map2Rel L)) . a = (id the carrier of (MonSet L)) . a
then consider s being Function of L,(InclPoset (Ids L)) such that
A4: ( a = s & s is monotone & ( for x being Element of L holds s . x c= downarrow x ) ) by Def14;
((Rel2Map L) * (Map2Rel L)) . s in the carrier of (MonSet L) by A3, A4, FUNCT_2:7;
then consider Ls being Function of L,(InclPoset (Ids L)) such that
A5: ( ((Rel2Map L) * (Map2Rel L)) . s = Ls & Ls is monotone & ( for x being Element of L holds Ls . x c= downarrow x ) ) by Def14;
set AR = (Map2Rel L) . s;
(Map2Rel L) . s in the carrier of (InclPoset (Aux L)) by A3, A4, FUNCT_2:7;
then (Map2Rel L) . s in Aux L by YELLOW_1:1;
then reconsider AR = (Map2Rel L) . s as auxiliary Relation of L by Def9;
dom (Map2Rel L) = the carrier of (MonSet L) by FUNCT_2:def 1;
then Ls = (Rel2Map L) . AR by A3, A4, A5, FUNCT_1:23;
then A6: Ls = AR -below by Def15;
Ls = s
proof
A7: dom Ls = the carrier of L by FUNCT_2:def 1;
A8: dom s = the carrier of L by FUNCT_2:def 1;
now
let b be set ; :: thesis: ( b in the carrier of L implies Ls . b = s . b )
assume A9: b in the carrier of L ; :: thesis: Ls . b = s . b
then reconsider b' = b as Element of L ;
thus Ls . b = s . b :: thesis: verum
proof
thus Ls . b c= s . b :: according to XBOOLE_0:def 10 :: thesis: s . b c= Ls . b
proof
let d be set ; :: according to TARSKI:def 3 :: thesis: ( not d in Ls . b or d in s . b )
assume d in Ls . b ; :: thesis: d in s . b
then d in AR -below b' by A6, Def13;
then A10: [d,b'] in AR by Th13;
consider AR' being auxiliary Relation of L such that
A11: ( AR' = (Map2Rel L) . s & ( for d, b' being set holds
( [d,b'] in AR' iff ex d', b'' being Element of L ex s' being Function of L,(InclPoset (Ids L)) st
( d' = d & b'' = b' & s' = s & d' in s' . b'' ) ) ) ) by A3, A4, Def16;
consider d', b'' being Element of L, s' being Function of L,(InclPoset (Ids L)) such that
A12: ( d' = d & b'' = b' & s' = s & d' in s' . b'' ) by A10, A11;
thus d in s . b by A12; :: thesis: verum
end;
thus s . b c= Ls . b :: thesis: verum
proof
let d be set ; :: according to TARSKI:def 3 :: thesis: ( not d in s . b or d in Ls . b )
assume A13: d in s . b ; :: thesis: d in Ls . b
s . b in the carrier of (InclPoset (Ids L)) by A9, FUNCT_2:7;
then s . b in Ids L by YELLOW_1:1;
then consider X being Ideal of L such that
A14: s . b = X ;
reconsider d' = d as Element of L by A13, A14;
consider AR' being auxiliary Relation of L such that
A15: ( AR' = (Map2Rel L) . s & ( for d, b' being set holds
( [d,b'] in AR' iff ex d', b'' being Element of L ex s' being Function of L,(InclPoset (Ids L)) st
( d' = d & b'' = b' & s' = s & d' in s' . b'' ) ) ) ) by A3, A4, Def16;
[d',b'] in AR by A13, A15;
then d' in AR -below b' ;
hence d in Ls . b by A6, Def13; :: thesis: verum
end;
end;
end;
hence Ls = s by A7, A8, FUNCT_1:9; :: thesis: verum
end;
hence ((Rel2Map L) * (Map2Rel L)) . a = (id the carrier of (MonSet L)) . a by A3, A4, A5, FUNCT_1:35; :: thesis: verum
end;
hence (Rel2Map L) * (Map2Rel L) = id the carrier of (MonSet L) by A1, A2, FUNCT_1:9; :: thesis: verum