theorem
  for x be Element of [:C1,C2:],h be RMembership_Func of C1,C2 holds (
  Zmf(C1,C2)).x <= h.x & h.x <= (Umf(C1,C2)).x
proof
A1: Umf(C1,C2) = UMF [:C1,C2:];
  Zmf(C1,C2) = EMF [:C1,C2:];
  hence thesis by A1,FUZZY_1:16;
end;
