Problem: d(x,x) -> 0() f(x) -> d(x,f(x)) c() -> f(c()) Proof: Church Rosser Transformation Processor: strict: weak: critical peaks: 0 Redundant Rules Transformation: d(x,x) -> 0() f(x) -> d(x,f(x)) c() -> f(c()) f(c()) -> d(f(c()),f(c())) f(c()) -> d(c(),f(f(c()))) c() -> d(c(),f(c())) c() -> f(f(c())) d(d(x,x),0()) -> 0() d(0(),d(x,x)) -> 0() d(c(),f(c())) -> 0() d(f(c()),c()) -> 0() Nonconfluence Processor: terms: f(0()) *<- f(c()) ->* 0() Qed first automaton: final states: {1028} transitions: d(1029,1028) -> 1028* 0() -> 1029* f(1029) -> 1028* second automaton: final states: {7} transitions: 0() -> 7*