let S1, S2, T1, T2 be complete LATTICE; :: thesis: for f being directed-sups-preserving Function of S1,S2
for g being directed-sups-preserving Function of T1,T2 holds UPS (f,g) is directed-sups-preserving

let f be directed-sups-preserving Function of S1,S2; :: thesis: for g being directed-sups-preserving Function of T1,T2 holds UPS (f,g) is directed-sups-preserving
let g be directed-sups-preserving Function of T1,T2; :: thesis: UPS (f,g) is directed-sups-preserving
let A be Subset of (UPS (S2,T1)); :: according to WAYBEL_0:def 37 :: thesis: ( A is empty or not A is directed or UPS (f,g) preserves_sup_of A )
assume ( not A is empty & A is directed ) ; :: thesis: UPS (f,g) preserves_sup_of A
then reconsider H = A as non empty directed Subset of (UPS (S2,T1)) ;
assume ex_sup_of A, UPS (S2,T1) ; :: according to WAYBEL_0:def 31 :: thesis: ( ex_sup_of (UPS (f,g)) .: A, UPS (S1,T2) & "\/" (((UPS (f,g)) .: A),(UPS (S1,T2))) = (UPS (f,g)) . ("\/" (A,(UPS (S2,T1)))) )
thus ex_sup_of (UPS (f,g)) .: A, UPS (S1,T2) by YELLOW_0:17; :: thesis: "\/" (((UPS (f,g)) .: A),(UPS (S1,T2))) = (UPS (f,g)) . ("\/" (A,(UPS (S2,T1))))
UPS (S2,T1) is full SubRelStr of T1 |^ the carrier of S2 by Def4;
then reconsider B = H as non empty directed Subset of (T1 |^ the carrier of S2) by YELLOW_2:7;
A1: UPS (S1,T2) is full SubRelStr of T2 |^ the carrier of S1 by Def4;
then reconsider fgsA = (UPS (f,g)) . (sup H) as Element of (T2 |^ the carrier of S1) by YELLOW_0:58;
the carrier of (UPS (S1,T2)) c= the carrier of (T2 |^ the carrier of S1) by A1, YELLOW_0:def 13;
then reconsider fgA = (UPS (f,g)) .: H as non empty Subset of (T2 |^ the carrier of S1) by XBOOLE_1:1;
A2: T2 |^ the carrier of S1 = product ( the carrier of S1 --> T2) by YELLOW_1:def 5;
then A3: dom (sup fgA) = the carrier of S1 by WAYBEL_3:27;
A4: T1 |^ the carrier of S2 = product ( the carrier of S2 --> T1) by YELLOW_1:def 5;
A5: now :: thesis: for s being object st s in the carrier of S1 holds
(sup fgA) . s = fgsA . s
reconsider BB = B as directed Subset of (product ( the carrier of S2 --> T1)) by A4;
let s be object ; :: thesis: ( s in the carrier of S1 implies (sup fgA) . s = fgsA . s )
A6: dom f = the carrier of S1 by FUNCT_2:def 1;
assume s in the carrier of S1 ; :: thesis: (sup fgA) . s = fgsA . s
then reconsider x = s as Element of S1 ;
reconsider sH = sup H as directed-sups-preserving Function of S2,T1 by Def4;
A7: ( the carrier of S2 --> T1) . (f . x) = T1 ;
dom sH = the carrier of S2 by FUNCT_2:def 1;
then f . x in dom sH ;
then A8: x in dom (sH * f) by A6, FUNCT_1:11;
A9: pi (fgA,x) = g .: (pi (A,(f . x)))
proof
thus pi (fgA,x) c= g .: (pi (A,(f . x))) :: according to XBOOLE_0:def 10 :: thesis: g .: (pi (A,(f . x))) c= pi (fgA,x)
proof
let a be object ; :: according to TARSKI:def 3 :: thesis: ( not a in pi (fgA,x) or a in g .: (pi (A,(f . x))) )
A10: dom g = the carrier of T1 by FUNCT_2:def 1;
assume a in pi (fgA,x) ; :: thesis: a in g .: (pi (A,(f . x)))
then consider F being Function such that
A11: F in fgA and
A12: a = F . x by CARD_3:def 6;
consider G being object such that
A13: G in dom (UPS (f,g)) and
A14: G in H and
A15: F = (UPS (f,g)) . G by A11, FUNCT_1:def 6;
reconsider G = G as directed-sups-preserving Function of S2,T1 by A13, Def4;
A16: G . (f . x) in pi (A,(f . x)) by A14, CARD_3:def 6;
A17: dom f = the carrier of S1 by FUNCT_2:def 1;
dom G = the carrier of S2 by FUNCT_2:def 1;
then f . x in dom G ;
then A18: x in dom (G * f) by A17, FUNCT_1:11;
a = ((g * G) * f) . x by A12, A15, Def5
.= (g * (G * f)) . x by RELAT_1:36
.= g . ((G * f) . x) by A18, FUNCT_1:13
.= g . (G . (f . x)) by A17, FUNCT_1:13 ;
hence a in g .: (pi (A,(f . x))) by A10, A16, FUNCT_1:def 6; :: thesis: verum
end;
let a be object ; :: according to TARSKI:def 3 :: thesis: ( not a in g .: (pi (A,(f . x))) or a in pi (fgA,x) )
A19: dom (UPS (f,g)) = the carrier of (UPS (S2,T1)) by FUNCT_2:def 1;
assume a in g .: (pi (A,(f . x))) ; :: thesis: a in pi (fgA,x)
then consider F being object such that
F in dom g and
A20: F in pi (A,(f . x)) and
A21: a = g . F by FUNCT_1:def 6;
consider G being Function such that
A22: G in A and
A23: F = G . (f . x) by A20, CARD_3:def 6;
reconsider G = G as directed-sups-preserving Function of S2,T1 by A22, Def4;
(g * G) * f = (UPS (f,g)) . G by Def5;
then A24: (g * G) * f in fgA by A22, A19, FUNCT_1:def 6;
A25: dom f = the carrier of S1 by FUNCT_2:def 1;
dom G = the carrier of S2 by FUNCT_2:def 1;
then f . x in dom G ;
then A26: x in dom (G * f) by A25, FUNCT_1:11;
a = g . ((G * f) . x) by A21, A23, A25, FUNCT_1:13
.= (g * (G * f)) . x by A26, FUNCT_1:13
.= ((g * G) * f) . x by RELAT_1:36 ;
hence a in pi (fgA,x) by A24, CARD_3:def 6; :: thesis: verum
end;
A27: ex_sup_of pi (B,(f . x)),T1 by YELLOW_0:17;
A28: pi (BB,(f . x)) is directed by YELLOW16:35;
A29: g preserves_sup_of pi (B,(f . x)) by A28, WAYBEL_0:def 37;
( the carrier of S1 --> T2) . x = T2 ;
hence (sup fgA) . s = sup (pi (fgA,x)) by A2, YELLOW16:33, YELLOW_0:17
.= g . (sup (pi (B,(f . x)))) by A9, A29, A27
.= g . ((sup B) . (f . x)) by A4, A7, YELLOW16:33, YELLOW_0:17
.= g . (sH . (f . x)) by Th27
.= g . ((sH * f) . x) by A6, FUNCT_1:13
.= (g * (sH * f)) . x by A8, FUNCT_1:13
.= ((g * sH) * f) . s by RELAT_1:36
.= fgsA . s by Def5 ;
:: thesis: verum
end;
A30: dom fgsA = the carrier of S1 by A2, WAYBEL_3:27;
thus sup ((UPS (f,g)) .: A) = sup fgA by Th27
.= (UPS (f,g)) . (sup A) by A3, A30, A5 ; :: thesis: verum