YES Problem: c(c(z,y,a()),a(),a()) -> b(z,y) f(c(x,y,z)) -> c(z,f(b(y,z)),a()) b(z,b(c(a(),y,a()),f(f(x)))) -> c(c(y,a(),z),z,x) Proof: DP Processor: DPs: c#(c(z,y,a()),a(),a()) -> b#(z,y) f#(c(x,y,z)) -> b#(y,z) f#(c(x,y,z)) -> f#(b(y,z)) f#(c(x,y,z)) -> c#(z,f(b(y,z)),a()) b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(y,a(),z) b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(c(y,a(),z),z,x) TRS: c(c(z,y,a()),a(),a()) -> b(z,y) f(c(x,y,z)) -> c(z,f(b(y,z)),a()) b(z,b(c(a(),y,a()),f(f(x)))) -> c(c(y,a(),z),z,x) TDG Processor: DPs: c#(c(z,y,a()),a(),a()) -> b#(z,y) f#(c(x,y,z)) -> b#(y,z) f#(c(x,y,z)) -> f#(b(y,z)) f#(c(x,y,z)) -> c#(z,f(b(y,z)),a()) b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(y,a(),z) b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(c(y,a(),z),z,x) TRS: c(c(z,y,a()),a(),a()) -> b(z,y) f(c(x,y,z)) -> c(z,f(b(y,z)),a()) b(z,b(c(a(),y,a()),f(f(x)))) -> c(c(y,a(),z),z,x) graph: f#(c(x,y,z)) -> f#(b(y,z)) -> f#(c(x,y,z)) -> c#(z,f(b(y,z)),a()) f#(c(x,y,z)) -> f#(b(y,z)) -> f#(c(x,y,z)) -> f#(b(y,z)) f#(c(x,y,z)) -> f#(b(y,z)) -> f#(c(x,y,z)) -> b#(y,z) f#(c(x,y,z)) -> b#(y,z) -> b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(c(y,a(),z),z,x) f#(c(x,y,z)) -> b#(y,z) -> b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(y,a(),z) f#(c(x,y,z)) -> c#(z,f(b(y,z)),a()) -> c#(c(z,y,a()),a(),a()) -> b#(z,y) b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(c(y,a(),z),z,x) -> c#(c(z,y,a()),a(),a()) -> b#(z,y) b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(y,a(),z) -> c#(c(z,y,a()),a(),a()) -> b#(z,y) c#(c(z,y,a()),a(),a()) -> b#(z,y) -> b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(c(y,a(),z),z,x) c#(c(z,y,a()),a(),a()) -> b#(z,y) -> b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(y,a(),z) SCC Processor: #sccs: 2 #rules: 4 #arcs: 10/36 DPs: f#(c(x,y,z)) -> f#(b(y,z)) TRS: c(c(z,y,a()),a(),a()) -> b(z,y) f(c(x,y,z)) -> c(z,f(b(y,z)),a()) b(z,b(c(a(),y,a()),f(f(x)))) -> c(c(y,a(),z),z,x) Usable Rule Processor: DPs: f#(c(x,y,z)) -> f#(b(y,z)) TRS: b(z,b(c(a(),y,a()),f(f(x)))) -> c(c(y,a(),z),z,x) c(c(z,y,a()),a(),a()) -> b(z,y) Arctic Interpretation Processor: dimension: 2 usable rules: b(z,b(c(a(),y,a()),f(f(x)))) -> c(c(y,a(),z),z,x) c(c(z,y,a()),a(),a()) -> b(z,y) interpretation: [f#](x0) = [0 -&]x0, [0 -&] [-&] [f](x0) = [1 1 ]x0 + [1 ], [-& -&] [0 0] [b](x0, x1) = [1 1 ]x0 + [1 0]x1, [-& 1 ] [-& -&] [1 1 ] [0 ] [c](x0, x1, x2) = [0 1 ]x0 + [0 1 ]x1 + [-& -&]x2 + [-&], [0] [a] = [1] orientation: f#(c(x,y,z)) = [-& 1 ]x + [1 1]z + [0] >= [0 0]z = f#(b(y,z)) [2 2] [1 2] [-& -&] [3] [1 1 ] [1 2] [-& -&] [3] b(z,b(c(a(),y,a()),f(f(x)))) = [3 3]x + [1 2]y + [1 1 ]z + [3] >= [-& -&]x + [1 2]y + [1 1 ]z + [3] = c(c(y,a(),z),z,x) [1 2] [1 2] [2] [0 0] [-& -&] c(c(z,y,a()),a(),a()) = [1 2]y + [1 2]z + [2] >= [1 0]y + [1 1 ]z = b(z,y) problem: DPs: TRS: b(z,b(c(a(),y,a()),f(f(x)))) -> c(c(y,a(),z),z,x) c(c(z,y,a()),a(),a()) -> b(z,y) Qed DPs: b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(y,a(),z) c#(c(z,y,a()),a(),a()) -> b#(z,y) b#(z,b(c(a(),y,a()),f(f(x)))) -> c#(c(y,a(),z),z,x) TRS: c(c(z,y,a()),a(),a()) -> b(z,y) f(c(x,y,z)) -> c(z,f(b(y,z)),a()) b(z,b(c(a(),y,a()),f(f(x)))) -> c(c(y,a(),z),z,x) Subterm Criterion Processor: simple projection: pi(c) = [0,0,1] pi(b) = [0,0,0,1,1] pi(c#) = [0,0,0,1,1] pi(b#) = [0,0,0,1,1] problem: DPs: TRS: c(c(z,y,a()),a(),a()) -> b(z,y) f(c(x,y,z)) -> c(z,f(b(y,z)),a()) b(z,b(c(a(),y,a()),f(f(x)))) -> c(c(y,a(),z),z,x) Qed