reserve x1,x2,z for set;
reserve A,B for non empty set;
reserve f,g,h for Element of Funcs(A,REAL);

theorem
  RealFuncZero(A) <> RealFuncUnit(A)
proof
  set a = the Element of A;
  (RealFuncZero(A)).a=0;
  hence thesis by FUNCOP_1:7;
end;
