set A = W -SUP_category ;
set B = W -INF_category ;
set F = W UpperAdj ;
A16: ex x being non empty set st x in W by SETFAM_1:def 11;
deffunc H1( object of (W -SUP_category )) -> RelStr = latt W;
deffunc H2( object of (W -SUP_category ), object of (W -SUP_category ), Morphism of W,c2) -> Function of (latt c2),(latt W) = UpperAdj (@ c3);
A17: for a being object of (W -SUP_category ) holds (W UpperAdj ) . a = H1(a) by Def7;
A18: for a, b being object of (W -SUP_category ) st <^a,b^> <> {} holds
for f being Morphism of a,b holds (W UpperAdj ) . f = H2(a,b,f) by Def7;
A19: for a, b being object of (W -SUP_category ) st H1(a) = H1(b) holds
a = b ;
A20: now
let a, b be object of (W -SUP_category ); :: thesis: ( <^a,b^> <> {} implies for f, g being Morphism of a,b st H2(a,b,f) = H2(a,b,g) holds
f = g )

assume A21: <^a,b^> <> {} ; :: thesis: for f, g being Morphism of a,b st H2(a,b,f) = H2(a,b,g) holds
f = g

let f, g be Morphism of a,b; :: thesis: ( H2(a,b,f) = H2(a,b,g) implies f = g )
A22: ( @ f = f & @ g = g ) by A21, YELLOW21:def 7;
then A23: ( latt a is complete & latt b is complete & @ f is sups-preserving & @ g is sups-preserving ) by A16, A21, Def5;
assume H2(a,b,f) = H2(a,b,g) ; :: thesis: f = g
hence f = LowerAdj (UpperAdj (@ g)) by A22, A23, Th11
.= g by A22, A23, Th11 ;
:: thesis: verum
end;
A24: now
let a, b be object of (W -INF_category ); :: thesis: ( <^a,b^> <> {} implies for f being Morphism of a,b ex c, d being object of (W -SUP_category ) ex g being Morphism of c,d st
( b = H1(c) & a = H1(d) & <^c,d^> <> {} & f = H2(c,d,g) ) )

assume A25: <^a,b^> <> {} ; :: thesis: for f being Morphism of a,b ex c, d being object of (W -SUP_category ) ex g being Morphism of c,d st
( b = H1(c) & a = H1(d) & <^c,d^> <> {} & f = H2(c,d,g) )

let f be Morphism of a,b; :: thesis: ex c, d being object of (W -SUP_category ) ex g being Morphism of c,d st
( b = H1(c) & a = H1(d) & <^c,d^> <> {} & f = H2(c,d,g) )

( latt a is strict & latt a is complete & the carrier of (latt a) in W & latt b is strict & latt b is complete & the carrier of (latt b) in W ) by A16, Def4;
then reconsider c = latt b, d = latt a as object of (W -SUP_category ) by Def5;
take c = c; :: thesis: ex d being object of (W -SUP_category ) ex g being Morphism of c,d st
( b = H1(c) & a = H1(d) & <^c,d^> <> {} & f = H2(c,d,g) )

take d = d; :: thesis: ex g being Morphism of c,d st
( b = H1(c) & a = H1(d) & <^c,d^> <> {} & f = H2(c,d,g) )

A26: ( latt c = c & latt d = d ) ;
A27: f = @ f by A25, YELLOW21:def 7;
then A28: @ f is infs-preserving by A16, A25, Def4;
then A29: ( LowerAdj (@ f) is monotone & LowerAdj (@ f) is sups-preserving ) by A26;
then A30: LowerAdj (@ f) in <^c,d^> by A16, Def5;
reconsider g = LowerAdj (@ f) as Morphism of c,d by A16, A29, Def5;
take g = g; :: thesis: ( b = H1(c) & a = H1(d) & <^c,d^> <> {} & f = H2(c,d,g) )
thus ( b = H1(c) & a = H1(d) & <^c,d^> <> {} ) by A16, A29, Def5; :: thesis: f = H2(c,d,g)
g = @ g by A30, YELLOW21:def 7;
hence f = H2(c,d,g) by A27, A28, Th10; :: thesis: verum
end;
thus W UpperAdj is bijective from YELLOW18:sch 12(A17, A18, A19, A20, A24); :: thesis: verum