YES Problem: f(a,empty()) -> g(a,empty()) f(a,cons(x,k)) -> f(cons(x,a),k) g(empty(),d) -> d g(cons(x,k),d) -> g(k,cons(x,d)) Proof: DP Processor: DPs: f#(a,empty()) -> g#(a,empty()) f#(a,cons(x,k)) -> f#(cons(x,a),k) g#(cons(x,k),d) -> g#(k,cons(x,d)) TRS: f(a,empty()) -> g(a,empty()) f(a,cons(x,k)) -> f(cons(x,a),k) g(empty(),d) -> d g(cons(x,k),d) -> g(k,cons(x,d)) Matrix Interpretation Processor: dim=1 interpretation: [g#](x0, x1) = 2x0 + x1 + 1/2, [f#](x0, x1) = 2x0 + 3x1 + 2, [cons](x0, x1) = 3x0 + x1 + 1/2, [g](x0, x1) = 2x0 + 2x1 + 7/2, [f](x0, x1) = 2x0 + 2x1 + 7/2, [empty] = 3/2 orientation: f#(a,empty()) = 2a + 13/2 >= 2a + 2 = g#(a,empty()) f#(a,cons(x,k)) = 2a + 3k + 9x + 7/2 >= 2a + 3k + 6x + 3 = f#(cons(x,a),k) g#(cons(x,k),d) = d + 2k + 6x + 3/2 >= d + 2k + 3x + 1 = g#(k,cons(x,d)) f(a,empty()) = 2a + 13/2 >= 2a + 13/2 = g(a,empty()) f(a,cons(x,k)) = 2a + 2k + 6x + 9/2 >= 2a + 2k + 6x + 9/2 = f(cons(x,a),k) g(empty(),d) = 2d + 13/2 >= d = d g(cons(x,k),d) = 2d + 2k + 6x + 9/2 >= 2d + 2k + 6x + 9/2 = g(k,cons(x,d)) problem: DPs: TRS: f(a,empty()) -> g(a,empty()) f(a,cons(x,k)) -> f(cons(x,a),k) g(empty(),d) -> d g(cons(x,k),d) -> g(k,cons(x,d)) Qed