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