0 QTRS
+(x, 0) → x +(x, s(y)) → s(+(x, y)) +(0, y) → y +(s(x), y) → s(+(x, y)) +(x, +(y, z)) → +(+(x, y), z) f(g(f(x))) → f(h(s(0), x)) f(g(h(x, y))) → f(h(s(x), y)) f(h(x, h(y, z))) → f(h(+(x, y), z))