TRS: { le(0(), y) -> true(), le(s(x), 0()) -> false(), le(s(x), s(y)) -> le(x, y), zero(0()) -> true(), zero(s(x)) -> false(), id(0()) -> 0(), id(s(x)) -> s(id(x)), minus(x, 0()) -> x, minus(s(x), s(y)) -> minus(x, y), mod(x, y) -> if_mod(zero(x), zero(y), le(y, x), id(x), id(y)), if_mod(true(), b1, b2, x, y) -> 0(), if_mod(false(), b1, b2, x, y) -> if2(b1, b2, x, y), if2(true(), b2, x, y) -> 0(), if2(false(), b2, x, y) -> if3(b2, x, y), if3(true(), x, y) -> mod(minus(x, y), s(y)), if3(false(), x, y) -> x} Fail