let C be non empty set ; for f, h, g being Membership_Func of C st max (g,h) c= & min (f,h) = EMF C holds
g c=
let f, h, g be Membership_Func of C; ( max (g,h) c= & min (f,h) = EMF C implies g c= )
assume that
A1:
max (g,h) c=
and
A2:
min (f,h) = EMF C
; g c=
let x be Element of C; FUZZY_1:def 2 f . x <= g . x
min (f,(max (g,h))) = f
by A1, Th26;
then f =
max ((min (f,g)),(min (f,h)))
by Th9
.=
min (f,g)
by A2, Th17
;
then
f . x = min ((f . x),(g . x))
by Def3;
hence
f . x <= g . x
by XXREAL_0:def 9; verum