YES Problem: f(s(x)) -> s(f(f(x))) f(x) -> c(x,x) Proof: DP Processor: DPs: f#(s(x)) -> f#(x) f#(s(x)) -> f#(f(x)) TRS: f(s(x)) -> s(f(f(x))) f(x) -> c(x,x) Arctic Interpretation Processor: dimension: 1 interpretation: [f#](x0) = 1x0, [c](x0, x1) = -16x0 + x1, [f](x0) = x0, [s](x0) = 3x0 orientation: f#(s(x)) = 4x >= 1x = f#(x) f#(s(x)) = 4x >= 1x = f#(f(x)) f(s(x)) = 3x >= 3x = s(f(f(x))) f(x) = x >= x = c(x,x) problem: DPs: TRS: f(s(x)) -> s(f(f(x))) f(x) -> c(x,x) Qed