YES Problem: f(a(),h(x)) -> f(g(x),h(x)) h(g(x)) -> h(a()) g(h(x)) -> g(x) h(h(x)) -> x Proof: DP Processor: DPs: f#(a(),h(x)) -> g#(x) f#(a(),h(x)) -> f#(g(x),h(x)) h#(g(x)) -> h#(a()) g#(h(x)) -> g#(x) TRS: f(a(),h(x)) -> f(g(x),h(x)) h(g(x)) -> h(a()) g(h(x)) -> g(x) h(h(x)) -> x Matrix Interpretation Processor: dim=3 interpretation: [h#](x0) = [0 0 1]x0, [g#](x0) = [1 0 1]x0 + [1], [f#](x0, x1) = [0 1 0]x0 + [1 0 0]x1 + [1], [0] [g](x0) = [0] [1], [0 1 0] [1 0 0] [1] [f](x0, x1) = [0 1 0]x0 + [1 0 0]x1 + [0] [0 1 0] [0 0 1] [0], [1 1 1] [0] [h](x0) = [1 0 0]x0 + [0] [0 0 1] [1], [0] [a] = [1] [0] orientation: f#(a(),h(x)) = [1 1 1]x + [2] >= [1 0 1]x + [1] = g#(x) f#(a(),h(x)) = [1 1 1]x + [2] >= [1 1 1]x + [1] = f#(g(x),h(x)) h#(g(x)) = [1] >= [0] = h#(a()) g#(h(x)) = [1 1 2]x + [2] >= [1 0 1]x + [1] = g#(x) [1 1 1] [2] [1 1 1] [1] f(a(),h(x)) = [1 1 1]x + [1] >= [1 1 1]x + [0] = f(g(x),h(x)) [0 0 1] [2] [0 0 1] [1] [1] [1] h(g(x)) = [0] >= [0] = h(a()) [2] [1] [0] [0] g(h(x)) = [0] >= [0] = g(x) [1] [1] [2 1 2] [1] h(h(x)) = [1 1 1]x + [0] >= x = x [0 0 1] [2] problem: DPs: TRS: f(a(),h(x)) -> f(g(x),h(x)) h(g(x)) -> h(a()) g(h(x)) -> g(x) h(h(x)) -> x Qed