YES Problem: a__f(X) -> g(h(f(X))) mark(f(X)) -> a__f(mark(X)) mark(g(X)) -> g(X) mark(h(X)) -> h(mark(X)) a__f(X) -> f(X) Proof: Arctic Interpretation Processor: dimension: 2 interpretation: [0 2] [mark](x0) = [0 1]x0, [0 -&] [g](x0) = [0 -&]x0, [h](x0) = x0, [0 -&] [f](x0) = [0 1 ]x0, [0 0] [a__f](x0) = [0 1]x0 orientation: [0 0] [0 -&] a__f(X) = [0 1]X >= [0 -&]X = g(h(f(X))) [2 3] [0 2] mark(f(X)) = [1 2]X >= [1 2]X = a__f(mark(X)) [2 -&] [0 -&] mark(g(X)) = [1 -&]X >= [0 -&]X = g(X) [0 2] [0 2] mark(h(X)) = [0 1]X >= [0 1]X = h(mark(X)) [0 0] [0 -&] a__f(X) = [0 1]X >= [0 1 ]X = f(X) problem: a__f(X) -> g(h(f(X))) mark(f(X)) -> a__f(mark(X)) mark(h(X)) -> h(mark(X)) a__f(X) -> f(X) Arctic Interpretation Processor: dimension: 2 interpretation: [0 2] [mark](x0) = [1 2]x0, [0 -&] [g](x0) = [-& -&]x0, [0 -&] [h](x0) = [0 1 ]x0, [0 -&] [f](x0) = [2 3 ]x0, [1 3] [a__f](x0) = [2 3]x0 orientation: [1 3] [0 -&] a__f(X) = [2 3]X >= [-& -&]X = g(h(f(X))) [4 5] [4 5] mark(f(X)) = [4 5]X >= [4 5]X = a__f(mark(X)) [2 3] [0 2] mark(h(X)) = [2 3]X >= [2 3]X = h(mark(X)) [1 3] [0 -&] a__f(X) = [2 3]X >= [2 3 ]X = f(X) problem: mark(f(X)) -> a__f(mark(X)) mark(h(X)) -> h(mark(X)) a__f(X) -> f(X) KBO Processor: weight function: w0 = 1 w(mark) = w(h) = w(f) = w(a__f) = 1 precedence: mark > a__f > h ~ f problem: Qed