TRS:
 { cond1(true(), x, y) -> cond2(gr(x, y), x, y),
   cond2(true(), x, y) -> cond3(gr(x, 0()), x, y),
  cond2(false(), x, y) -> cond4(gr(y, 0()), x, y),
   cond3(true(), x, y) -> cond3(gr(x, 0()), p(x), y),
  cond3(false(), x, y) -> cond1(and(gr(x, 0()), gr(y, 0())), x, y),
   cond4(true(), x, y) -> cond4(gr(y, 0()), x, p(y)),
  cond4(false(), x, y) -> cond1(and(gr(x, 0()), gr(y, 0())), x, y),
            gr(0(), x) -> false(),
         gr(s(x), 0()) -> true(),
        gr(s(x), s(y)) -> gr(x, y),
   and(true(), true()) -> true(),
       and(false(), x) -> false(),
       and(x, false()) -> false(),
                p(0()) -> 0(),
               p(s(x)) -> x}
 Fail