TRS:
 {     nonZero(0()) -> false(),
      nonZero(s(x)) -> true(),
             p(0()) -> 0(),
            p(s(x)) -> x,
          id_inc(x) -> x,
          id_inc(x) -> s(x),
          random(x) -> rand(x, 0()),
         rand(x, y) -> if(nonZero(x), x, y),
  if(false(), x, y) -> y,
   if(true(), x, y) -> rand(p(x), id_inc(y))}
 Fail