let C be non empty set ; for f, g, h being Membership_Func of C st g c= holds
min g,h c=
let f, g, h be Membership_Func of C; ( g c= implies min g,h c= )
assume A1:
g c=
; min g,h c=
let x be Element of C; FUZZY_1:def 3 (min f,h) . x <= (min g,h) . x
f . x <= g . x
by A1, Def3;
then
min (f . x),(h . x) <= min (g . x),(h . x)
by XXREAL_0:18;
then
(min f,h) . x <= min (g . x),(h . x)
by Def4;
hence
(min f,h) . x <= (min g,h) . x
by Def4; verum