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