Problem: f(0(),1(),X) -> h(X,X) h(0(),X) -> f(0(),X,X) g(X,Y) -> X g(X,Y) -> Y Proof: Unfolding Processor: loop length: 4 terms: h(0(),g(1(),0())) f(0(),g(1(),0()),g(1(),0())) f(0(),1(),g(1(),0())) h(g(1(),0()),g(1(),0())) context: [] substitution: Qed