theorem Th155:
  for R being right_zeroed non empty addLoopStr, a being Element of R,
  i be Integer st i = 1
  holds (Int-mult-left(R)).(i,a) = a
  proof
    let R be right_zeroed non empty addLoopStr,
        a be Element of R,
        i be Integer;
    assume i=1;
    hence (Int-mult-left(R)).(i,a) = 1 * a by Def23
    .= a by BINOM:13;
  end;
