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
  f c= EMF(C) implies f = EMF(C)
proof
  EMF(C) c= f by Th13;
  hence thesis by Lm1;
end;
