YES Problem: c(a(a(b(c(a(x1)))))) -> a(a(b(c(c(a(a(b(c(x1))))))))) Proof: DP Processor: DPs: c#(a(a(b(c(a(x1)))))) -> c#(x1) c#(a(a(b(c(a(x1)))))) -> c#(a(a(b(c(x1))))) c#(a(a(b(c(a(x1)))))) -> c#(c(a(a(b(c(x1)))))) TRS: c(a(a(b(c(a(x1)))))) -> a(a(b(c(c(a(a(b(c(x1))))))))) Arctic Interpretation Processor: dimension: 1 interpretation: [c#](x0) = x0 + 0, [b](x0) = -16x0 + 1, [c](x0) = x0 + 6, [a](x0) = 8x0 + 0 orientation: c#(a(a(b(c(a(x1)))))) = 8x1 + 17 >= x1 + 0 = c#(x1) c#(a(a(b(c(a(x1)))))) = 8x1 + 17 >= x1 + 17 = c#(a(a(b(c(x1))))) c#(a(a(b(c(a(x1)))))) = 8x1 + 17 >= x1 + 17 = c#(c(a(a(b(c(x1)))))) c(a(a(b(c(a(x1)))))) = 8x1 + 17 >= x1 + 17 = a(a(b(c(c(a(a(b(c(x1))))))))) problem: DPs: c#(a(a(b(c(a(x1)))))) -> c#(a(a(b(c(x1))))) c#(a(a(b(c(a(x1)))))) -> c#(c(a(a(b(c(x1)))))) TRS: c(a(a(b(c(a(x1)))))) -> a(a(b(c(c(a(a(b(c(x1))))))))) Matrix Interpretation Processor: dim=4 interpretation: [c#](x0) = [0 0 1 0]x0, [0 0 0 0] [0 1 0 0] [b](x0) = [1 0 0 1]x0 [0 0 0 0] , [1 0 0 0] [0 0 1 0] [c](x0) = [0 0 1 0]x0 [0 1 0 0] , [0 1 0 0] [1] [1 0 0 0] [0] [a](x0) = [0 0 1 0]x0 + [0] [0 0 0 0] [0] orientation: c#(a(a(b(c(a(x1)))))) = [1 1 0 0]x1 + [1] >= [1 1 0 0]x1 = c#(a(a(b(c(x1))))) c#(a(a(b(c(a(x1)))))) = [1 1 0 0]x1 + [1] >= [1 1 0 0]x1 = c#(c(a(a(b(c(x1)))))) [0 0 0 0] [1] [0 0 0 0] [1] [1 1 0 0] [1] [1 1 0 0] [1] c(a(a(b(c(a(x1)))))) = [1 1 0 0]x1 + [1] >= [1 1 0 0]x1 + [1] = a(a(b(c(c(a(a(b(c(x1))))))))) [0 0 1 0] [1] [0 0 0 0] [0] problem: DPs: TRS: c(a(a(b(c(a(x1)))))) -> a(a(b(c(c(a(a(b(c(x1))))))))) Qed