let C be non empty set ; for f, g, h being Membership_Func of C holds (min f,g) \ (min f,h) c=
let f, g, h be Membership_Func of C; (min f,g) \ (min f,h) c=
let c be Element of C; FUZZY_1:def 3 (min f,(g \ h)) . c <= ((min f,g) \ (min f,h)) . c
(1_minus h) . c <= max ((1_minus f) . c),((1_minus h) . c)
by XXREAL_0:25;
then
min ((min f,g) . c),((1_minus h) . c) <= min ((min f,g) . c),(max ((1_minus f) . c),((1_minus h) . c))
by XXREAL_0:18;
then
min ((min f,g) . c),((1_minus h) . c) <= min ((min f,g) . c),((max (1_minus f),(1_minus h)) . c)
by FUZZY_1:6;
then A1:
min ((min f,g) . c),((1_minus h) . c) <= (min (min f,g),(max (1_minus f),(1_minus h))) . c
by FUZZY_1:6;
(min f,(g \ h)) . c =
(min (min f,g),(1_minus h)) . c
by FUZZY_1:8
.=
min ((min f,g) . c),((1_minus h) . c)
by FUZZY_1:6
;
hence
(min f,(g \ h)) . c <= ((min f,g) \ (min f,h)) . c
by A1, FUZZY_1:12; verum