NO Problem: b(a(a(x))) -> a(x) a(a(a(x))) -> b(b(b(x))) b(b(x)) -> a(b(a(x))) Proof: Nonconfluence Processor: terms: b(a(b(a(f7())))) *<- b(b(b(f7()))) ->* a(b(a(b(f7())))) Qed first automaton: final states: {1} transitions: a(4) -> 5* a(2) -> 3* b(5) -> 1* b(3) -> 4* f7() -> 2* second automaton: final states: {6} transitions: a(10) -> 6* a(8) -> 9* b(9) -> 10* b(7) -> 8* f7() -> 7*