NO Problem: c() -> a() f(c()) -> f(h(b(),c())) a() -> c() c() -> h(f(c()),h(b(),h(h(b(),c()),a()))) c() -> b() Proof: Nonconfluence Processor: terms: h(f(c()),h(b(),h(h(b(),c()),a()))) *<- c() ->* b() Qed