Problem: f(0(),1(),g(x,y),z) -> f(g(x,y),g(x,y),g(x,y),h(x)) g(0(),1()) -> 0() g(0(),1()) -> 1() h(g(x,y)) -> h(x) Proof: Unfolding Processor: loop length: 3 terms: f(0(),1(),g(0(),1()),z) f(g(0(),1()),g(0(),1()),g(0(),1()),h(0())) f(0(),g(0(),1()),g(0(),1()),h(0())) context: [] substitution: z -> h(0()) Qed