YES Problem: a(a(x1)) -> b(c(x1)) b(b(x1)) -> c(d(x1)) b(x1) -> a(x1) c(c(x1)) -> d(f(x1)) d(d(x1)) -> f(f(f(x1))) d(x1) -> b(x1) f(f(x1)) -> g(a(x1)) g(g(x1)) -> a(x1) Proof: DP Processor: DPs: a#(a(x1)) -> c#(x1) a#(a(x1)) -> b#(c(x1)) b#(b(x1)) -> d#(x1) b#(b(x1)) -> c#(d(x1)) b#(x1) -> a#(x1) c#(c(x1)) -> f#(x1) c#(c(x1)) -> d#(f(x1)) d#(d(x1)) -> f#(x1) d#(d(x1)) -> f#(f(x1)) d#(d(x1)) -> f#(f(f(x1))) d#(x1) -> b#(x1) f#(f(x1)) -> a#(x1) f#(f(x1)) -> g#(a(x1)) g#(g(x1)) -> a#(x1) TRS: a(a(x1)) -> b(c(x1)) b(b(x1)) -> c(d(x1)) b(x1) -> a(x1) c(c(x1)) -> d(f(x1)) d(d(x1)) -> f(f(f(x1))) d(x1) -> b(x1) f(f(x1)) -> g(a(x1)) g(g(x1)) -> a(x1) Matrix Interpretation Processor: dim=3 interpretation: [g#](x0) = [0 2 0]x0 + [1], [f#](x0) = [2 0 2]x0 + [3], [d#](x0) = [2 0 0]x0 + [3], [b#](x0) = [2 0 0]x0 + [2], [c#](x0) = [0 0 2]x0, [a#](x0) = [2 0 0]x0 + [1], [0 2 0] [0] [g](x0) = [1 1 1]x0 + [1] [0 2 0] [0], [0 0 0] [0] [f](x0) = [0 0 2]x0 + [3] [2 0 1] [0], [2 0 1] [2] [d](x0) = [3 0 0]x0 + [0] [2 0 1] [1], [2 0 1] [2] [b](x0) = [0 0 0]x0 + [0] [2 0 1] [1], [1 0 1] [0] [c](x0) = [0 0 0]x0 + [0] [1 0 1] [2], [2 0 1] [1] [a](x0) = [0 0 0]x0 + [0] [2 0 1] [1] orientation: a#(a(x1)) = [4 0 2]x1 + [3] >= [0 0 2]x1 = c#(x1) a#(a(x1)) = [4 0 2]x1 + [3] >= [2 0 2]x1 + [2] = b#(c(x1)) b#(b(x1)) = [4 0 2]x1 + [6] >= [2 0 0]x1 + [3] = d#(x1) b#(b(x1)) = [4 0 2]x1 + [6] >= [4 0 2]x1 + [2] = c#(d(x1)) b#(x1) = [2 0 0]x1 + [2] >= [2 0 0]x1 + [1] = a#(x1) c#(c(x1)) = [2 0 2]x1 + [4] >= [2 0 2]x1 + [3] = f#(x1) c#(c(x1)) = [2 0 2]x1 + [4] >= [3] = d#(f(x1)) d#(d(x1)) = [4 0 2]x1 + [7] >= [2 0 2]x1 + [3] = f#(x1) d#(d(x1)) = [4 0 2]x1 + [7] >= [4 0 2]x1 + [3] = f#(f(x1)) d#(d(x1)) = [4 0 2]x1 + [7] >= [4 0 2]x1 + [3] = f#(f(f(x1))) d#(x1) = [2 0 0]x1 + [3] >= [2 0 0]x1 + [2] = b#(x1) f#(f(x1)) = [4 0 2]x1 + [3] >= [2 0 0]x1 + [1] = a#(x1) f#(f(x1)) = [4 0 2]x1 + [3] >= [1] = g#(a(x1)) g#(g(x1)) = [2 2 2]x1 + [3] >= [2 0 0]x1 + [1] = a#(x1) [6 0 3] [4] [3 0 3] [4] a(a(x1)) = [0 0 0]x1 + [0] >= [0 0 0]x1 + [0] = b(c(x1)) [6 0 3] [4] [3 0 3] [3] [6 0 3] [7] [4 0 2] [3] b(b(x1)) = [0 0 0]x1 + [0] >= [0 0 0]x1 + [0] = c(d(x1)) [6 0 3] [6] [4 0 2] [5] [2 0 1] [2] [2 0 1] [1] b(x1) = [0 0 0]x1 + [0] >= [0 0 0]x1 + [0] = a(x1) [2 0 1] [1] [2 0 1] [1] [2 0 2] [2] [2 0 1] [2] c(c(x1)) = [0 0 0]x1 + [0] >= [0 0 0]x1 + [0] = d(f(x1)) [2 0 2] [4] [2 0 1] [1] [6 0 3] [7] [0 0 0] [0] d(d(x1)) = [6 0 3]x1 + [6] >= [4 0 2]x1 + [3] = f(f(f(x1))) [6 0 3] [6] [2 0 1] [0] [2 0 1] [2] [2 0 1] [2] d(x1) = [3 0 0]x1 + [0] >= [0 0 0]x1 + [0] = b(x1) [2 0 1] [1] [2 0 1] [1] [0 0 0] [0] [0 0 0] [0] f(f(x1)) = [4 0 2]x1 + [3] >= [4 0 2]x1 + [3] = g(a(x1)) [2 0 1] [0] [0 0 0] [0] [2 2 2] [2] [2 0 1] [1] g(g(x1)) = [1 5 1]x1 + [2] >= [0 0 0]x1 + [0] = a(x1) [2 2 2] [2] [2 0 1] [1] problem: DPs: TRS: a(a(x1)) -> b(c(x1)) b(b(x1)) -> c(d(x1)) b(x1) -> a(x1) c(c(x1)) -> d(f(x1)) d(d(x1)) -> f(f(f(x1))) d(x1) -> b(x1) f(f(x1)) -> g(a(x1)) g(g(x1)) -> a(x1) Qed