YES Problem: a(c(x1)) -> c(b(x1)) a(x1) -> b(b(b(x1))) b(c(b(x1))) -> a(c(x1)) Proof: DP Processor: DPs: a#(c(x1)) -> b#(x1) a#(x1) -> b#(x1) a#(x1) -> b#(b(x1)) a#(x1) -> b#(b(b(x1))) b#(c(b(x1))) -> a#(c(x1)) TRS: a(c(x1)) -> c(b(x1)) a(x1) -> b(b(b(x1))) b(c(b(x1))) -> a(c(x1)) Matrix Interpretation Processor: dim=1 interpretation: [b#](x0) = 2x0 + 2, [a#](x0) = 2x0 + 7, [b](x0) = x0 + 1, [a](x0) = x0 + 3, [c](x0) = 3x0 + 2 orientation: a#(c(x1)) = 6x1 + 11 >= 2x1 + 2 = b#(x1) a#(x1) = 2x1 + 7 >= 2x1 + 2 = b#(x1) a#(x1) = 2x1 + 7 >= 2x1 + 4 = b#(b(x1)) a#(x1) = 2x1 + 7 >= 2x1 + 6 = b#(b(b(x1))) b#(c(b(x1))) = 6x1 + 12 >= 6x1 + 11 = a#(c(x1)) a(c(x1)) = 3x1 + 5 >= 3x1 + 5 = c(b(x1)) a(x1) = x1 + 3 >= x1 + 3 = b(b(b(x1))) b(c(b(x1))) = 3x1 + 6 >= 3x1 + 5 = a(c(x1)) problem: DPs: TRS: a(c(x1)) -> c(b(x1)) a(x1) -> b(b(b(x1))) b(c(b(x1))) -> a(c(x1)) Qed