TRS: { lt(0(), s(x)) -> true(), lt(x, 0()) -> false(), lt(s(x), s(y)) -> lt(x, y), fac(x) -> help(x, 0()), help(x, c) -> if(lt(c, x), x, c), if(true(), x, c) -> times(s(c), help(x, s(c))), if(false(), x, c) -> s(0())} Fail