TRS: { p(0()) -> 0(), p(s(x)) -> x, le(0(), y) -> true(), le(s(x), 0()) -> false(), le(s(x), s(y)) -> le(x, y), minus(x, 0()) -> x, minus(x, s(y)) -> if(le(x, s(y)), 0(), p(minus(x, p(s(y))))), if(true(), x, y) -> x, if(false(), x, y) -> y} Fail