let C1, C2 be non empty set ; for x being Element of [:C1,C2:]
for h being RMembership_Func of C1,C2 holds
( (Zmf C1,C2) . x <= h . x & h . x <= (Umf C1,C2) . x )
A1:
Umf C1,C2 = UMF [:C1,C2:]
;
Zmf C1,C2 = EMF [:C1,C2:]
;
hence
for x being Element of [:C1,C2:]
for h being RMembership_Func of C1,C2 holds
( (Zmf C1,C2) . x <= h . x & h . x <= (Umf C1,C2) . x )
by A1, FUZZY_1:17; verum