NO Problem: h(f(b()),a()) -> h(f(h(c(),a())),f(a())) c() -> f(c()) c() -> h(f(b()),c()) a() -> c() f(a()) -> b() Proof: Nonconfluence Processor: terms: f(c()) *<- f(a()) ->* b() Qed first automaton: final states: {1} transitions: h(62,2) -> 2* b() -> 61* f(61) -> 62* f(2) -> 2,1 c() -> 2* second automaton: final states: {3} transitions: b() -> 3*