YES Problem: h(f(x,y)) -> f(f(a(),h(h(y))),x) Proof: DP Processor: DPs: h#(f(x,y)) -> h#(y) h#(f(x,y)) -> h#(h(y)) TRS: h(f(x,y)) -> f(f(a(),h(h(y))),x) Arctic Interpretation Processor: dimension: 2 interpretation: [h#](x0) = [0 -&]x0 + [0], [0] [a] = [1], [-& 0 ] [0] [h](x0) = [1 -&]x0 + [2], [-& -&] [0 1 ] [2] [f](x0, x1) = [0 1 ]x0 + [-& -&]x1 + [2] orientation: h#(f(x,y)) = [0 1]y + [2] >= [0 -&]y + [0] = h#(y) h#(f(x,y)) = [0 1]y + [2] >= [-& 0 ]y + [0] = h#(h(y)) [0 1 ] [-& -&] [2] [0 1 ] [-& -&] [2] h(f(x,y)) = [-& -&]x + [1 2 ]y + [3] >= [-& -&]x + [1 2 ]y + [3] = f(f(a(),h(h(y))),x) problem: DPs: h#(f(x,y)) -> h#(y) TRS: h(f(x,y)) -> f(f(a(),h(h(y))),x) Subterm Criterion Processor: simple projection: pi(h#) = 0 problem: DPs: TRS: h(f(x,y)) -> f(f(a(),h(h(y))),x) Qed