YES Problem: f(c(s(x),y)) -> f(c(x,s(y))) f(c(s(x),s(y))) -> g(c(x,y)) g(c(x,s(y))) -> g(c(s(x),y)) g(c(s(x),s(y))) -> f(c(x,y)) Proof: DP Processor: DPs: f#(c(s(x),y)) -> f#(c(x,s(y))) f#(c(s(x),s(y))) -> g#(c(x,y)) g#(c(x,s(y))) -> g#(c(s(x),y)) g#(c(s(x),s(y))) -> f#(c(x,y)) TRS: f(c(s(x),y)) -> f(c(x,s(y))) f(c(s(x),s(y))) -> g(c(x,y)) g(c(x,s(y))) -> g(c(s(x),y)) g(c(s(x),s(y))) -> f(c(x,y)) TDG Processor: DPs: f#(c(s(x),y)) -> f#(c(x,s(y))) f#(c(s(x),s(y))) -> g#(c(x,y)) g#(c(x,s(y))) -> g#(c(s(x),y)) g#(c(s(x),s(y))) -> f#(c(x,y)) TRS: f(c(s(x),y)) -> f(c(x,s(y))) f(c(s(x),s(y))) -> g(c(x,y)) g(c(x,s(y))) -> g(c(s(x),y)) g(c(s(x),s(y))) -> f(c(x,y)) graph: g#(c(s(x),s(y))) -> f#(c(x,y)) -> f#(c(s(x),s(y))) -> g#(c(x,y)) g#(c(s(x),s(y))) -> f#(c(x,y)) -> f#(c(s(x),y)) -> f#(c(x,s(y))) g#(c(x,s(y))) -> g#(c(s(x),y)) -> g#(c(s(x),s(y))) -> f#(c(x,y)) g#(c(x,s(y))) -> g#(c(s(x),y)) -> g#(c(x,s(y))) -> g#(c(s(x),y)) f#(c(s(x),s(y))) -> g#(c(x,y)) -> g#(c(s(x),s(y))) -> f#(c(x,y)) f#(c(s(x),s(y))) -> g#(c(x,y)) -> g#(c(x,s(y))) -> g#(c(s(x),y)) f#(c(s(x),y)) -> f#(c(x,s(y))) -> f#(c(s(x),s(y))) -> g#(c(x,y)) f#(c(s(x),y)) -> f#(c(x,s(y))) -> f#(c(s(x),y)) -> f#(c(x,s(y))) Matrix Interpretation Processor: dim=1 interpretation: [g#](x0) = 2x0 + 1/2, [f#](x0) = 2x0, [g](x0) = 0, [f](x0) = 0, [c](x0, x1) = 2x0 + 2x1, [s](x0) = x0 + 1 orientation: f#(c(s(x),y)) = 4x + 4y + 4 >= 4x + 4y + 4 = f#(c(x,s(y))) f#(c(s(x),s(y))) = 4x + 4y + 8 >= 4x + 4y + 1/2 = g#(c(x,y)) g#(c(x,s(y))) = 4x + 4y + 9/2 >= 4x + 4y + 9/2 = g#(c(s(x),y)) g#(c(s(x),s(y))) = 4x + 4y + 17/2 >= 4x + 4y = f#(c(x,y)) f(c(s(x),y)) = 0 >= 0 = f(c(x,s(y))) f(c(s(x),s(y))) = 0 >= 0 = g(c(x,y)) g(c(x,s(y))) = 0 >= 0 = g(c(s(x),y)) g(c(s(x),s(y))) = 0 >= 0 = f(c(x,y)) problem: DPs: f#(c(s(x),y)) -> f#(c(x,s(y))) g#(c(x,s(y))) -> g#(c(s(x),y)) TRS: f(c(s(x),y)) -> f(c(x,s(y))) f(c(s(x),s(y))) -> g(c(x,y)) g(c(x,s(y))) -> g(c(s(x),y)) g(c(s(x),s(y))) -> f(c(x,y)) SCC Processor: #sccs: 2 #rules: 2 #arcs: 8/4 DPs: f#(c(s(x),y)) -> f#(c(x,s(y))) TRS: f(c(s(x),y)) -> f(c(x,s(y))) f(c(s(x),s(y))) -> g(c(x,y)) g(c(x,s(y))) -> g(c(s(x),y)) g(c(s(x),s(y))) -> f(c(x,y)) Arctic Interpretation Processor: dimension: 1 interpretation: [f#](x0) = x0, [g](x0) = 1, [f](x0) = 1, [c](x0, x1) = x0, [s](x0) = 1x0 orientation: f#(c(s(x),y)) = 1x >= x = f#(c(x,s(y))) f(c(s(x),y)) = 1 >= 1 = f(c(x,s(y))) f(c(s(x),s(y))) = 1 >= 1 = g(c(x,y)) g(c(x,s(y))) = 1 >= 1 = g(c(s(x),y)) g(c(s(x),s(y))) = 1 >= 1 = f(c(x,y)) problem: DPs: TRS: f(c(s(x),y)) -> f(c(x,s(y))) f(c(s(x),s(y))) -> g(c(x,y)) g(c(x,s(y))) -> g(c(s(x),y)) g(c(s(x),s(y))) -> f(c(x,y)) Qed DPs: g#(c(x,s(y))) -> g#(c(s(x),y)) TRS: f(c(s(x),y)) -> f(c(x,s(y))) f(c(s(x),s(y))) -> g(c(x,y)) g(c(x,s(y))) -> g(c(s(x),y)) g(c(s(x),s(y))) -> f(c(x,y)) Arctic Interpretation Processor: dimension: 1 interpretation: [g#](x0) = x0 + 0, [g](x0) = 4, [f](x0) = 4, [c](x0, x1) = x1 + 0, [s](x0) = 3x0 + 4 orientation: g#(c(x,s(y))) = 3y + 4 >= y + 0 = g#(c(s(x),y)) f(c(s(x),y)) = 4 >= 4 = f(c(x,s(y))) f(c(s(x),s(y))) = 4 >= 4 = g(c(x,y)) g(c(x,s(y))) = 4 >= 4 = g(c(s(x),y)) g(c(s(x),s(y))) = 4 >= 4 = f(c(x,y)) problem: DPs: TRS: f(c(s(x),y)) -> f(c(x,s(y))) f(c(s(x),s(y))) -> g(c(x,y)) g(c(x,s(y))) -> g(c(s(x),y)) g(c(s(x),s(y))) -> f(c(x,y)) Qed