YES Problem: b(c(x1)) -> a(x1) b(b(x1)) -> a(c(x1)) a(x1) -> c(b(x1)) c(c(c(x1))) -> b(x1) Proof: DP Processor: DPs: b#(c(x1)) -> a#(x1) b#(b(x1)) -> c#(x1) b#(b(x1)) -> a#(c(x1)) a#(x1) -> b#(x1) a#(x1) -> c#(b(x1)) c#(c(c(x1))) -> b#(x1) TRS: b(c(x1)) -> a(x1) b(b(x1)) -> a(c(x1)) a(x1) -> c(b(x1)) c(c(c(x1))) -> b(x1) Matrix Interpretation Processor: dim=1 interpretation: [c#](x0) = 2x0, [a#](x0) = 2x0 + 9/2, [b#](x0) = 2x0 + 3, [a](x0) = x0 + 3, [b](x0) = x0 + 2, [c](x0) = x0 + 1 orientation: b#(c(x1)) = 2x1 + 5 >= 2x1 + 9/2 = a#(x1) b#(b(x1)) = 2x1 + 7 >= 2x1 = c#(x1) b#(b(x1)) = 2x1 + 7 >= 2x1 + 13/2 = a#(c(x1)) a#(x1) = 2x1 + 9/2 >= 2x1 + 3 = b#(x1) a#(x1) = 2x1 + 9/2 >= 2x1 + 4 = c#(b(x1)) c#(c(c(x1))) = 2x1 + 4 >= 2x1 + 3 = b#(x1) b(c(x1)) = x1 + 3 >= x1 + 3 = a(x1) b(b(x1)) = x1 + 4 >= x1 + 4 = a(c(x1)) a(x1) = x1 + 3 >= x1 + 3 = c(b(x1)) c(c(c(x1))) = x1 + 3 >= x1 + 2 = b(x1) problem: DPs: TRS: b(c(x1)) -> a(x1) b(b(x1)) -> a(c(x1)) a(x1) -> c(b(x1)) c(c(c(x1))) -> b(x1) Qed