YES TRS: f(X) -> cons(X,n__f(n__g(X))) g(0()) -> s(0()) g(s(X)) -> s(s(g(X))) sel(0(),cons(X,Y)) -> X sel(s(X),cons(Y,Z)) -> sel(X,activate(Z)) f(X) -> n__f(X) g(X) -> n__g(X) activate(n__f(X)) -> f(activate(X)) activate(n__g(X)) -> g(activate(X)) activate(X) -> X linear polynomial interpretations on N: f_A(x1) = x1 + 1 f#_A(x1) = 1 cons_A(x1,x2) = x1 + x2 cons#_A(x1,x2) = 0 n__f_A(x1) = x1 + 1 n__f#_A(x1) = 0 n__g_A(x1) = 0 n__g#_A(x1) = 0 g_A(x1) = 0 g#_A(x1) = 1 0_A = 1 0#_A = 0 s_A(x1) = 0 s#_A(x1) = 0 sel_A(x1,x2) = x2 sel#_A(x1,x2) = 3 activate_A(x1) = x1 activate#_A(x1) = 2 precedence: cons = sel > activate > f = g > n__f = n__g = 0 = s