YES Problem: f(s(x)) -> s(f(f(p(s(x))))) f(0()) -> 0() p(s(x)) -> x Proof: DP Processor: DPs: f#(s(x)) -> p#(s(x)) f#(s(x)) -> f#(p(s(x))) f#(s(x)) -> f#(f(p(s(x)))) TRS: f(s(x)) -> s(f(f(p(s(x))))) f(0()) -> 0() p(s(x)) -> x TDG Processor: DPs: f#(s(x)) -> p#(s(x)) f#(s(x)) -> f#(p(s(x))) f#(s(x)) -> f#(f(p(s(x)))) TRS: f(s(x)) -> s(f(f(p(s(x))))) f(0()) -> 0() p(s(x)) -> x graph: f#(s(x)) -> f#(p(s(x))) -> f#(s(x)) -> f#(f(p(s(x)))) f#(s(x)) -> f#(p(s(x))) -> f#(s(x)) -> f#(p(s(x))) f#(s(x)) -> f#(p(s(x))) -> f#(s(x)) -> p#(s(x)) f#(s(x)) -> f#(f(p(s(x)))) -> f#(s(x)) -> f#(f(p(s(x)))) f#(s(x)) -> f#(f(p(s(x)))) -> f#(s(x)) -> f#(p(s(x))) f#(s(x)) -> f#(f(p(s(x)))) -> f#(s(x)) -> p#(s(x)) SCC Processor: #sccs: 1 #rules: 2 #arcs: 6/9 DPs: f#(s(x)) -> f#(p(s(x))) f#(s(x)) -> f#(f(p(s(x)))) TRS: f(s(x)) -> s(f(f(p(s(x))))) f(0()) -> 0() p(s(x)) -> x Matrix Interpretation Processor: dim=3 interpretation: [f#](x0) = [1 0 0]x0, [0] [0] = [0] [0], [0 1 0] [p](x0) = [0 0 2]x0 [0 0 1] , [1 0 0] [0] [f](x0) = [1 0 0]x0 + [2] [1 0 1] [0], [3 0 0] [3] [s](x0) = [1 0 0]x0 + [0] [0 1 1] [1] orientation: f#(s(x)) = [3 0 0]x + [3] >= [1 0 0]x = f#(p(s(x))) f#(s(x)) = [3 0 0]x + [3] >= [1 0 0]x = f#(f(p(s(x)))) [3 0 0] [3] [3 0 0] [3] f(s(x)) = [3 0 0]x + [5] >= [1 0 0]x + [0] = s(f(f(p(s(x))))) [3 1 1] [4] [3 1 1] [4] [0] [0] f(0()) = [2] >= [0] = 0() [0] [0] [1 0 0] [0] p(s(x)) = [0 2 2]x + [2] >= x = x [0 1 1] [1] problem: DPs: TRS: f(s(x)) -> s(f(f(p(s(x))))) f(0()) -> 0() p(s(x)) -> x Qed