YES Problem: b(c(a(x1))) -> a(b(a(b(c(x1))))) b(x1) -> c(c(x1)) c(d(x1)) -> a(b(c(a(x1)))) a(a(x1)) -> a(c(b(a(x1)))) Proof: DP Processor: DPs: b#(c(a(x1))) -> c#(x1) b#(c(a(x1))) -> b#(c(x1)) b#(c(a(x1))) -> a#(b(c(x1))) b#(c(a(x1))) -> b#(a(b(c(x1)))) b#(c(a(x1))) -> a#(b(a(b(c(x1))))) b#(x1) -> c#(x1) b#(x1) -> c#(c(x1)) c#(d(x1)) -> a#(x1) c#(d(x1)) -> c#(a(x1)) c#(d(x1)) -> b#(c(a(x1))) c#(d(x1)) -> a#(b(c(a(x1)))) a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> c#(b(a(x1))) a#(a(x1)) -> a#(c(b(a(x1)))) TRS: b(c(a(x1))) -> a(b(a(b(c(x1))))) b(x1) -> c(c(x1)) c(d(x1)) -> a(b(c(a(x1)))) a(a(x1)) -> a(c(b(a(x1)))) Matrix Interpretation Processor: dim=5 interpretation: [a#](x0) = [1 1 1 1 0]x0 + [1], [c#](x0) = [0 1 0 1 1]x0, [b#](x0) = [1 1 0 1 1]x0 + [1], [0 0 0 0 0] [0] [0 1 1 1 1] [1] [d](x0) = [0 0 0 1 0]x0 + [0] [1 0 0 1 0] [1] [1 0 0 1 0] [1], [0 1 0 0 1] [0 0 0 0 0] [b](x0) = [1 0 0 0 0]x0 [0 0 0 0 1] [0 0 0 0 0] , [0 0 1 1 0] [0 0 0 0 1] [c](x0) = [0 0 0 0 1]x0 [0 1 0 0 0] [0 0 0 0 0] , [0 0 0 0 1] [0] [0 1 0 0 1] [0] [a](x0) = [0 0 0 0 0]x0 + [1] [0 0 1 1 0] [0] [0 0 0 0 0] [0] orientation: b#(c(a(x1))) = [0 1 1 1 1]x1 + [2] >= [0 1 0 1 1]x1 = c#(x1) b#(c(a(x1))) = [0 1 1 1 1]x1 + [2] >= [0 1 1 1 1]x1 + [1] = b#(c(x1)) b#(c(a(x1))) = [0 1 1 1 1]x1 + [2] >= [0 0 1 1 1]x1 + [1] = a#(b(c(x1))) b#(c(a(x1))) = [0 1 1 1 1]x1 + [2] >= [0 0 1 1 0]x1 + [1] = b#(a(b(c(x1)))) b#(c(a(x1))) = [0 1 1 1 1]x1 + [2] >= [1] = a#(b(a(b(c(x1))))) b#(x1) = [1 1 0 1 1]x1 + [1] >= [0 1 0 1 1]x1 = c#(x1) b#(x1) = [1 1 0 1 1]x1 + [1] >= [0 1 0 0 1]x1 = c#(c(x1)) c#(d(x1)) = [2 1 1 3 1]x1 + [3] >= [1 1 1 1 0]x1 + [1] = a#(x1) c#(d(x1)) = [2 1 1 3 1]x1 + [3] >= [0 1 1 1 1]x1 = c#(a(x1)) c#(d(x1)) = [2 1 1 3 1]x1 + [3] >= [0 1 1 1 1]x1 + [2] = b#(c(a(x1))) c#(d(x1)) = [2 1 1 3 1]x1 + [3] >= [0 0 1 1 0]x1 + [2] = a#(b(c(a(x1)))) a#(a(x1)) = [0 1 1 1 2]x1 + [2] >= [0 1 1 1 2]x1 + [1] = b#(a(x1)) a#(a(x1)) = [0 1 1 1 2]x1 + [2] >= [0] = c#(b(a(x1))) a#(a(x1)) = [0 1 1 1 2]x1 + [2] >= [0 0 0 0 1]x1 + [1] = a#(c(b(a(x1)))) [0 0 0 0 0] [0] [0] [0 0 0 0 0] [0] [0] b(c(a(x1))) = [0 0 1 1 0]x1 + [1] >= [1] = a(b(a(b(c(x1))))) [0 0 0 0 0] [0] [0] [0 0 0 0 0] [0] [0] [0 1 0 0 1] [0 1 0 0 1] [0 0 0 0 0] [0 0 0 0 0] b(x1) = [1 0 0 0 0]x1 >= [0 0 0 0 0]x1 = c(c(x1)) [0 0 0 0 1] [0 0 0 0 1] [0 0 0 0 0] [0 0 0 0 0] [1 0 0 2 0] [1] [0 0 0 0 0] [0] [1 0 0 1 0] [1] [0 0 0 0 0] [0] c(d(x1)) = [1 0 0 1 0]x1 + [1] >= [0 0 0 0 0]x1 + [1] = a(b(c(a(x1)))) [0 1 1 1 1] [1] [0 0 1 1 0] [1] [0 0 0 0 0] [0] [0 0 0 0 0] [0] [0 0 0 0 0] [0] [0] [0 1 0 0 1] [0] [0] a(a(x1)) = [0 0 0 0 0]x1 + [1] >= [1] = a(c(b(a(x1)))) [0 0 1 1 0] [1] [0] [0 0 0 0 0] [0] [0] problem: DPs: TRS: b(c(a(x1))) -> a(b(a(b(c(x1))))) b(x1) -> c(c(x1)) c(d(x1)) -> a(b(c(a(x1)))) a(a(x1)) -> a(c(b(a(x1)))) Qed