0 QTRS
-(x, 0) → x -(s(x), s(y)) → -(x, y) min(x, 0) → 0 min(0, y) → 0 min(s(x), s(y)) → s(min(x, y)) twice(0) → 0 twice(s(x)) → s(s(twice(x))) f(s(x), s(y)) → f(-(y, min(x, y)), s(twice(min(x, y)))) f(s(x), s(y)) → f(-(x, min(x, y)), s(twice(min(x, y))))