0 QTRS
-(x, 0) → x -(0, s(y)) → 0 -(s(x), s(y)) → -(x, y) lt(x, 0) → false lt(0, s(y)) → true lt(s(x), s(y)) → lt(x, y) if(true, x, y) → x if(false, x, y) → y div(x, 0) → 0 div(0, y) → 0 div(s(x), s(y)) → if(lt(x, y), 0, s(div(-(x, y), s(y))))