theorem Th48:
  for T being non empty set, R being real-membered set, f being Function of T,R
  holds incl(f,0) = T --> 0
  proof
    let T be non empty set;
    let R be real-membered set;
    let f be Function of T,R;
    reconsider z = 0 as Element of TOP-REAL 0;
    incl(f,0) = T --> z
    proof
      let x be Element of T;
      thus incl(f,0).x = (T --> z).x;
    end;
    hence thesis;
  end;
