TRS:
 {        minus(x, y) -> cond(ge(x, s(y)), x, y),
  cond(false(), x, y) -> 0(),
   cond(true(), x, y) -> s(minus(x, s(y))),
           ge(u, 0()) -> true(),
        ge(0(), s(v)) -> false(),
       ge(s(u), s(v)) -> ge(u, v)}
 Fail