let L be Lattice; :: thesis: ( (LattRel L) ~ = LattRel (L .: ) & (LattPOSet L) ~ = LattPOSet (L .: ) )
A1: ( LattRel L = { [p,q] where p, q is Element of L : p [= q } & LattRel (L .: ) = { [p',q'] where p', q' is Element of (L .: ) : p' [= q' } & L .: = LattStr(# H1(L),H3(L),H2(L) #) & LattStr(# the carrier of L,the L_join of L,the L_meet of L #) = LattStr(# H1(L),H2(L),H3(L) #) ) by FILTER_1:def 8, LATTICE2:def 2;
thus (LattRel L) ~ = LattRel (L .: ) :: thesis: (LattPOSet L) ~ = LattPOSet (L .: )
proof
let x, y be set ; :: according to RELAT_1:def 2 :: thesis: ( ( not [x,y] in (LattRel L) ~ or [x,y] in LattRel (L .: ) ) & ( not [x,y] in LattRel (L .: ) or [x,y] in (LattRel L) ~ ) )
thus ( [x,y] in (LattRel L) ~ implies [x,y] in LattRel (L .: ) ) :: thesis: ( not [x,y] in LattRel (L .: ) or [x,y] in (LattRel L) ~ )
proof
assume [x,y] in (LattRel L) ~ ; :: thesis: [x,y] in LattRel (L .: )
then [y,x] in LattRel L by RELAT_1:def 7;
then consider p, q being Element of L such that
A2: ( [y,x] = [p,q] & p [= q ) by A1;
reconsider p' = p, q' = q as Element of (L .: ) by A1;
( x = q & y = p & q' [= p' ) by A2, LATTICE2:53, ZFMISC_1:33;
hence [x,y] in LattRel (L .: ) by A1; :: thesis: verum
end;
assume [x,y] in LattRel (L .: ) ; :: thesis: [x,y] in (LattRel L) ~
then consider p', q' being Element of (L .: ) such that
A3: ( [x,y] = [p',q'] & p' [= q' ) by A1;
reconsider p = p', q = q' as Element of L by A1;
( x = p & y = q & q [= p ) by A3, LATTICE2:54, ZFMISC_1:33;
then [y,x] in LattRel L by A1;
hence [x,y] in (LattRel L) ~ by RELAT_1:def 7; :: thesis: verum
end;
hence (LattPOSet L) ~ = LattPOSet (L .: ) by A1; :: thesis: verum