MAYBE
Trs:
 {          times(x, 0()) -> 0(),
  times(x, plus(y, s(z))) -> plus(times(x, plus(y, times(s(z), 0()))), times(x, s(z))),
           times(x, s(y)) -> plus(times(x, y), x),
             plus(x, 0()) -> x,
            plus(x, s(y)) -> s(plus(x, y))}
 Comment:
  We consider a duplicating trs.
  FAIL:
   Open