YES Problem: active(f(f(a()))) -> mark(f(g(f(a())))) active(f(X)) -> f(active(X)) f(mark(X)) -> mark(f(X)) proper(f(X)) -> f(proper(X)) proper(a()) -> ok(a()) proper(g(X)) -> g(proper(X)) f(ok(X)) -> ok(f(X)) g(ok(X)) -> ok(g(X)) top(mark(X)) -> top(proper(X)) top(ok(X)) -> top(active(X)) Proof: DP Processor: DPs: active#(f(f(a()))) -> g#(f(a())) active#(f(f(a()))) -> f#(g(f(a()))) active#(f(X)) -> active#(X) active#(f(X)) -> f#(active(X)) f#(mark(X)) -> f#(X) proper#(f(X)) -> proper#(X) proper#(f(X)) -> f#(proper(X)) proper#(g(X)) -> proper#(X) proper#(g(X)) -> g#(proper(X)) f#(ok(X)) -> f#(X) g#(ok(X)) -> g#(X) top#(mark(X)) -> proper#(X) top#(mark(X)) -> top#(proper(X)) top#(ok(X)) -> active#(X) top#(ok(X)) -> top#(active(X)) TRS: active(f(f(a()))) -> mark(f(g(f(a())))) active(f(X)) -> f(active(X)) f(mark(X)) -> mark(f(X)) proper(f(X)) -> f(proper(X)) proper(a()) -> ok(a()) proper(g(X)) -> g(proper(X)) f(ok(X)) -> ok(f(X)) g(ok(X)) -> ok(g(X)) top(mark(X)) -> top(proper(X)) top(ok(X)) -> top(active(X)) Matrix Interpretation Processor: dim=2 interpretation: [top#](x0) = [1 1]x0, [proper#](x0) = [1 0]x0 + [1], [f#](x0) = [1 0]x0, [g#](x0) = [1 0]x0, [active#](x0) = [1 0]x0, [2 3] [top](x0) = [0 2]x0, [1] [ok](x0) = x0 + [0], [1] [proper](x0) = x0 + [0], [1] [mark](x0) = x0 + [1], [1 0] [1] [g](x0) = [0 0]x0 + [0], [active](x0) = x0, [1 1] [1] [f](x0) = [0 2]x0 + [2], [1] [a] = [0] orientation: active#(f(f(a()))) = 5 >= 2 = g#(f(a())) active#(f(f(a()))) = 5 >= 3 = f#(g(f(a()))) active#(f(X)) = [1 1]X + [1] >= [1 0]X = active#(X) active#(f(X)) = [1 1]X + [1] >= [1 0]X = f#(active(X)) f#(mark(X)) = [1 0]X + [1] >= [1 0]X = f#(X) proper#(f(X)) = [1 1]X + [2] >= [1 0]X + [1] = proper#(X) proper#(f(X)) = [1 1]X + [2] >= [1 0]X + [1] = f#(proper(X)) proper#(g(X)) = [1 0]X + [2] >= [1 0]X + [1] = proper#(X) proper#(g(X)) = [1 0]X + [2] >= [1 0]X + [1] = g#(proper(X)) f#(ok(X)) = [1 0]X + [1] >= [1 0]X = f#(X) g#(ok(X)) = [1 0]X + [1] >= [1 0]X = g#(X) top#(mark(X)) = [1 1]X + [2] >= [1 0]X + [1] = proper#(X) top#(mark(X)) = [1 1]X + [2] >= [1 1]X + [1] = top#(proper(X)) top#(ok(X)) = [1 1]X + [1] >= [1 0]X = active#(X) top#(ok(X)) = [1 1]X + [1] >= [1 1]X = top#(active(X)) [5] [5] active(f(f(a()))) = [6] >= [3] = mark(f(g(f(a())))) [1 1] [1] [1 1] [1] active(f(X)) = [0 2]X + [2] >= [0 2]X + [2] = f(active(X)) [1 1] [3] [1 1] [2] f(mark(X)) = [0 2]X + [4] >= [0 2]X + [3] = mark(f(X)) [1 1] [2] [1 1] [2] proper(f(X)) = [0 2]X + [2] >= [0 2]X + [2] = f(proper(X)) [2] [2] proper(a()) = [0] >= [0] = ok(a()) [1 0] [2] [1 0] [2] proper(g(X)) = [0 0]X + [0] >= [0 0]X + [0] = g(proper(X)) [1 1] [2] [1 1] [2] f(ok(X)) = [0 2]X + [2] >= [0 2]X + [2] = ok(f(X)) [1 0] [2] [1 0] [2] g(ok(X)) = [0 0]X + [0] >= [0 0]X + [0] = ok(g(X)) [2 3] [5] [2 3] [2] top(mark(X)) = [0 2]X + [2] >= [0 2]X + [0] = top(proper(X)) [2 3] [2] [2 3] top(ok(X)) = [0 2]X + [0] >= [0 2]X = top(active(X)) problem: DPs: TRS: active(f(f(a()))) -> mark(f(g(f(a())))) active(f(X)) -> f(active(X)) f(mark(X)) -> mark(f(X)) proper(f(X)) -> f(proper(X)) proper(a()) -> ok(a()) proper(g(X)) -> g(proper(X)) f(ok(X)) -> ok(f(X)) g(ok(X)) -> ok(g(X)) top(mark(X)) -> top(proper(X)) top(ok(X)) -> top(active(X)) Qed