NO Problem: a(x) -> b(x) b(b(c(x))) -> c(a(c(a(a(x))))) c(c(x)) -> x Proof: Nonconfluence Processor: terms: b(b(f3())) *<- b(b(c(c(f3())))) ->* c(a(c(a(a(c(f3())))))) Qed first automaton: final states: {3} transitions: f3() -> 4* b(4) -> 5* b(5) -> 3* second automaton: final states: {6} transitions: f3() -> 7* a(47) -> 148* a(7) -> 46* a(8) -> 9* a(150) -> 151* a(46) -> 47* a(9) -> 10* a(11) -> 12* a(148) -> 149* a(48) -> 49* b(46) -> 47* b(8) -> 9* b(9) -> 10* b(7) -> 46* b(11) -> 12* b(150) -> 151* b(148) -> 149* b(47) -> 148* b(48) -> 49* c(7) -> 8* c(12) -> 6* c(151) -> 12* c(49) -> 10* c(149) -> 150* c(47) -> 48* c(10) -> 11* 151 -> 6* 49 -> 11*