NO Problem: c(b(a(b(a(x1))))) -> a(b(a(b(a(b(c(b(c(x1))))))))) Proof: Unfolding Processor: loop length: 4 terms: c(b(a(b(a(b(a(b(a(b(a(b(a(x82))))))))))))) a(b(a(b(a(b(c(b(c(b(a(b(a(b(a(b(a(x82))))))))))))))))) a(b(a(b(a(b(c(b(a(b(a(b(a(b(c(b(c(b(a(b(a(x82))))))))))))))))))))) a(b(a(b(a(b(c(b(a(b(a(b(a(b(c(b(a(b(a(b(a(b(c(b(c(x82))))))))))))))))))))))))) context: a(b(a(b(a(b([])))))) substitution: x82 -> b(c(b(c(b(a(b(c(b(c(x82)))))))))) Qed