NO Problem: c() -> f(f(c())) h(h(h(b(),b()),f(f(a()))),f(f(f(a())))) -> a() b() -> h(h(f(a()),c()),f(a())) Proof: Nonconfluence Processor: terms: h(h(h(h(h(f(a()),c()),f(a())),b()),f(f(a()))),f(f(f(a())))) *<- h(h(h(b(),b()),f(f(a()))),f(f(f(a())))) ->* a() Qed