TRS:
 {           p(0()) -> 0(),
            p(s(x)) -> x,
         le(0(), y) -> true(),
      le(s(x), 0()) -> false(),
     le(s(x), s(y)) -> le(x, y),
        minus(x, y) -> if(le(x, y), x, y),
   if(true(), x, y) -> 0(),
  if(false(), x, y) -> s(minus(p(x), y))}
 Fail