NO Problem: a(x1) -> x1 a(x1) -> b(x1) b(b(c(x1))) -> c(c(a(a(a(x1))))) c(x1) -> x1 Proof: Unfolding Processor: loop length: 10 terms: a(b(c(b(c(c(x140853)))))) b(b(c(b(c(c(x140853)))))) c(c(a(a(a(b(c(c(x140853)))))))) c(c(a(b(a(b(c(c(x140853)))))))) c(c(a(b(b(b(c(c(x140853)))))))) c(c(a(b(c(c(a(a(a(c(x140853)))))))))) c(c(a(b(c(a(a(a(c(x140853))))))))) c(c(a(b(c(b(a(a(c(x140853))))))))) c(c(a(b(c(b(b(a(c(x140853))))))))) c(c(a(b(c(b(b(b(c(x140853))))))))) context: c(c([])) substitution: x140853 -> a(a(a(x140853))) Qed