YES Problem: b(c(b(c(a(a(x1)))))) -> a(a(a(b(c(b(c(b(c(x1))))))))) Proof: DP Processor: DPs: b#(c(b(c(a(a(x1)))))) -> b#(c(x1)) b#(c(b(c(a(a(x1)))))) -> b#(c(b(c(x1)))) b#(c(b(c(a(a(x1)))))) -> b#(c(b(c(b(c(x1)))))) TRS: b(c(b(c(a(a(x1)))))) -> a(a(a(b(c(b(c(b(c(x1))))))))) Matrix Interpretation Processor: dim=3 interpretation: [b#](x0) = [0 2 0]x0 + [2], [0 2 0] [b](x0) = [0 1 0]x0 [0 0 1] , [0 0 0] [c](x0) = [0 0 1]x0 [0 1 0] , [0 1 2] [2] [a](x0) = [1 0 0]x0 + [0] [0 0 0] [0] orientation: b#(c(b(c(a(a(x1)))))) = [0 2 4]x1 + [6] >= [0 0 2]x1 + [2] = b#(c(x1)) b#(c(b(c(a(a(x1)))))) = [0 2 4]x1 + [6] >= [0 2 0]x1 + [2] = b#(c(b(c(x1)))) b#(c(b(c(a(a(x1)))))) = [0 2 4]x1 + [6] >= [0 0 2]x1 + [2] = b#(c(b(c(b(c(x1)))))) [0 2 4] [4] [0 2 1] [4] b(c(b(c(a(a(x1)))))) = [0 1 2]x1 + [2] >= [0 0 2]x1 + [2] = a(a(a(b(c(b(c(b(c(x1))))))))) [0 0 0] [0] [0 0 0] [0] problem: DPs: TRS: b(c(b(c(a(a(x1)))))) -> a(a(a(b(c(b(c(b(c(x1))))))))) Qed