let C be non empty set ; :: thesis: for f, h, g being Membership_Func of C holds f * (max (g,h)) = max ((f * g),(f * h))
let f, h, g be Membership_Func of C; :: thesis: f * (max (g,h)) = max ((f * g),(f * h))
A1: C = dom (max ((f * g),(f * h))) by FUNCT_2:def 1;
A2: for c being Element of C st c in C holds
(f * (max (g,h))) . c = (max ((f * g),(f * h))) . c
proof
let c be Element of C; :: thesis: ( c in C implies (f * (max (g,h))) . c = (max ((f * g),(f * h))) . c )
(f * (max (g,h))) . c = (f . c) * ((max (g,h)) . c) by Def2
.= (f . c) * (max ((g . c),(h . c))) by FUZZY_1:5
.= max (((f . c) * (g . c)),((f . c) * (h . c))) by Lm2, Th1
.= max (((f * g) . c),((f . c) * (h . c))) by Def2
.= max (((f * g) . c),((f * h) . c)) by Def2 ;
hence ( c in C implies (f * (max (g,h))) . c = (max ((f * g),(f * h))) . c ) by FUZZY_1:5; :: thesis: verum
end;
C = dom (f * (max (g,h))) by FUNCT_2:def 1;
hence f * (max (g,h)) = max ((f * g),(f * h)) by A1, A2, PARTFUN1:5; :: thesis: verum