TRS: { leq(0(), y) -> true(), leq(s(x), 0()) -> false(), leq(s(x), s(y)) -> leq(x, y), if(true(), x, y) -> x, if(false(), x, y) -> y, -(x, 0()) -> x, -(s(x), s(y)) -> -(x, y), mod(0(), y) -> 0(), mod(s(x), 0()) -> 0(), mod(s(x), s(y)) -> if(leq(y, x), mod(-(s(x), s(y)), s(y)), s(x))} Fail