reserve x, y for object, X, X1, X2 for set;

theorem Th2:
  E_Funcs(X) is Subset of E_PFuncs(X)
proof
  E_Funcs(X) c= E_PFuncs(X)
  proof
    let x be object;
    assume x in E_Funcs(X);
    then x is Function of X,ExtREAL by Def11;
    hence thesis by Def10;
  end;
  hence thesis;
end;
