MAYBE Problem: f(g(x)) -> g(g(f(x))) g(s(x)) -> s(s(g(x))) s(x) -> h(0(),x) s(x) -> h(x,0()) f(0()) -> 0() s(s(s(0()))) -> f(s(0())) f(s(0())) -> s(0()) h(f(x),g(x)) -> f(s(x)) g(x) -> h(h(h(h(x,x),x),x),x) f(s(s(x))) -> h(f(x),g(h(x,x))) s(0()) -> r(0()) s(s(s(0()))) -> r(s(0())) r(s(0())) -> s(0()) g(x) -> r(x) s(0()) -> p(0()) s(s(0())) -> p(s(0())) p(s(0())) -> 0() s(s(s(s(s(0()))))) -> p(s(s(0()))) p(s(s(0()))) -> s(s(s(0()))) h(p(x),g(x)) -> p(s(x)) s(0()) -> k(0()) s(s(p(p(a())))) -> s(k(p(a()))) s(k(p(a()))) -> p(p(a())) g(x) -> k(x) a() -> 0() s(h(r(k(p(x))),r(x))) -> h(r(r(p(x))),k(x)) Proof: Open