NO Problem: b() -> f(h(c(),b())) f(f(f(c()))) -> b() c() -> a() Proof: Nonconfluence Processor: terms: f(f(f(a()))) *<- f(f(f(c()))) ->* b() Qed first automaton: final states: {1} transitions: f(3) -> 4* f(4) -> 1* f(2) -> 3* a() -> 2* second automaton: final states: {5} transitions: f(8) -> 5* b() -> 5* c() -> 7* a() -> 7* h(7,5) -> 8*