let X be non empty set ; :: thesis: for f, g being Membership_Func of X holds f c=
let f, g be Membership_Func of X; :: thesis: f c=
let x be Element of X; :: according to FUZZY_1:def 2 :: thesis: (min (f,g)) . x <= f . x
(min (f,g)) . x = min ((f . x),(g . x)) by FUZZY_1:def 3;
hence (min (f,g)) . x <= f . x by XXREAL_0:17; :: thesis: verum