reserve x,y,y1,y2 for set;
reserve C for non empty set;
reserve c for Element of C;
reserve f,h,g,h1 for Membership_Func of C;

theorem Th15:
  for x be Element of C,h be Membership_Func of C holds (EMF(C)).x
  <= h.x & h.x <= (UMF(C)).x by Th13,Th14,Def2;
