YES Problem: b(a(),f(b(b(z,y),a()))) -> z c(c(z,x,a()),a(),y) -> f(f(c(y,a(),f(c(z,y,x))))) f(f(c(a(),y,z))) -> b(y,b(z,z)) Proof: DP Processor: DPs: c#(c(z,x,a()),a(),y) -> c#(z,y,x) c#(c(z,x,a()),a(),y) -> f#(c(z,y,x)) c#(c(z,x,a()),a(),y) -> c#(y,a(),f(c(z,y,x))) c#(c(z,x,a()),a(),y) -> f#(c(y,a(),f(c(z,y,x)))) c#(c(z,x,a()),a(),y) -> f#(f(c(y,a(),f(c(z,y,x))))) f#(f(c(a(),y,z))) -> b#(z,z) f#(f(c(a(),y,z))) -> b#(y,b(z,z)) TRS: b(a(),f(b(b(z,y),a()))) -> z c(c(z,x,a()),a(),y) -> f(f(c(y,a(),f(c(z,y,x))))) f(f(c(a(),y,z))) -> b(y,b(z,z)) Matrix Interpretation Processor: dim=3 usable rules: b(a(),f(b(b(z,y),a()))) -> z c(c(z,x,a()),a(),y) -> f(f(c(y,a(),f(c(z,y,x))))) f(f(c(a(),y,z))) -> b(y,b(z,z)) interpretation: [f#](x0) = [1], [c#](x0, x1, x2) = [1 0 0]x0 + [1 0 0]x1 + [1 0 0]x2 + [1], [b#](x0, x1) = [0], [1 0 0] [1 1 0] [0 0 1] [1] [c](x0, x1, x2) = [0 0 0]x0 + [0 0 0]x1 + [0 0 0]x2 + [0] [0 0 0] [1 1 1] [1 0 0] [0], [0 1 0] [f](x0) = [0 0 1]x0 [0 0 1] , [0 0 0] [1 0 0] [b](x0, x1) = [1 1 1]x0 + [1 0 0]x1 [0 1 1] [1 0 0] , [0] [a] = [0] [0] orientation: c#(c(z,x,a()),a(),y) = [1 1 0]x + [1 0 0]y + [1 0 0]z + [2] >= [1 0 0]x + [1 0 0]y + [1 0 0]z + [1] = c#(z,y,x) c#(c(z,x,a()),a(),y) = [1 1 0]x + [1 0 0]y + [1 0 0]z + [2] >= [1] = f#(c(z,y,x)) c#(c(z,x,a()),a(),y) = [1 1 0]x + [1 0 0]y + [1 0 0]z + [2] >= [1 0 0]y + [1] = c#(y,a(),f(c(z,y,x))) c#(c(z,x,a()),a(),y) = [1 1 0]x + [1 0 0]y + [1 0 0]z + [2] >= [1] = f#(c(y,a(),f(c(z,y,x)))) c#(c(z,x,a()),a(),y) = [1 1 0]x + [1 0 0]y + [1 0 0]z + [2] >= [1] = f#(f(c(y,a(),f(c(z,y,x))))) f#(f(c(a(),y,z))) = [1] >= [0] = b#(z,z) f#(f(c(a(),y,z))) = [1] >= [0] = b#(y,b(z,z)) [3 0 0] [1 2 2] b(a(),f(b(b(z,y),a()))) = [3 0 0]y + [1 2 2]z >= z = z [3 0 0] [1 2 2] [1 1 0] [0 0 1] [1 0 0] [2] [0] c(c(z,x,a()),a(),y) = [0 0 0]x + [0 0 0]y + [0 0 0]z + [0] >= [0] = f(f(c(y,a(),f(c(z,y,x))))) [0 0 0] [1 0 0] [0 0 0] [0] [0] [1 1 1] [1 0 0] [0 0 0] [1 0 0] f(f(c(a(),y,z))) = [1 1 1]y + [1 0 0]z >= [1 1 1]y + [1 0 0]z = b(y,b(z,z)) [1 1 1] [1 0 0] [0 1 1] [1 0 0] problem: DPs: TRS: b(a(),f(b(b(z,y),a()))) -> z c(c(z,x,a()),a(),y) -> f(f(c(y,a(),f(c(z,y,x))))) f(f(c(a(),y,z))) -> b(y,b(z,z)) Qed