TRS:
 {cond(true(), x, y) -> cond(gr(x, y), x, add(x, y)),
          gr(0(), x) -> false(),
       gr(s(x), 0()) -> true(),
      gr(s(x), s(y)) -> gr(x, y),
         add(0(), x) -> x,
        add(s(x), y) -> s(add(x, y))}
 Fail