let C be non empty set ; for f, h, g being Membership_Func of C st f c= & g c= holds
min (f,g) c=
let f, h, g be Membership_Func of C; ( f c= & g c= implies min (f,g) c= )
assume A1:
( f c= & g c= )
; min (f,g) c=
let x be Element of C; FUZZY_1:def 2 h . x <= (min (f,g)) . x
( h . x <= f . x & h . x <= g . x )
by A1;
then
h . x <= min ((f . x),(g . x))
by XXREAL_0:20;
hence
h . x <= (min (f,g)) . x
by Def3; verum