YES Problem: w(r(x)) -> r(w(x)) b(r(x)) -> r(b(x)) b(w(x)) -> w(b(x)) Proof: DP Processor: DPs: w#(r(x)) -> w#(x) b#(r(x)) -> b#(x) b#(w(x)) -> b#(x) b#(w(x)) -> w#(b(x)) TRS: w(r(x)) -> r(w(x)) b(r(x)) -> r(b(x)) b(w(x)) -> w(b(x)) KBO Processor: weight function: w0 = 1 w(b#) = w(b) = w(w) = w(r) = 1 w(w#) = 0 precedence: w# > b > w > b# ~ r problem: DPs: TRS: Qed