
theorem Th3:
  for R being left_zeroed right_add-cancelable right-distributive
     non empty doubleLoopStr, I being right-ideal non empty Subset of R holds
  0.R in I
proof
  let R be left_zeroed right_add-cancelable right-distributive non empty
  doubleLoopStr;
  let I be right-ideal non empty Subset of R;
  set a = the Element of I;
  a*0.R in I by Def3;
  hence thesis by BINOM:2;
end;
