NO Problem: a(x1) -> x1 a(b(x1)) -> a(c(b(b(a(a(x1)))))) b(x1) -> x1 c(c(x1)) -> x1 Proof: Unfolding Processor: loop length: 7 terms: a(b(b(x10285))) a(c(b(b(a(a(b(x10285))))))) a(c(b(a(a(b(x10285)))))) a(c(a(a(b(x10285))))) a(c(a(b(x10285)))) a(c(a(c(b(b(a(a(x10285)))))))) a(c(c(b(b(a(a(x10285))))))) context: [] substitution: x10285 -> a(a(x10285)) Qed