YES Problem: f(s(x)) -> s(f(f(x))) f(x) -> c(x,x) Proof: DP Processor: DPs: f#(s(x)) -> f#(x) f#(s(x)) -> f#(f(x)) TRS: f(s(x)) -> s(f(f(x))) f(x) -> c(x,x) KBO Processor: argument filtering: pi(s) = [0] pi(f) = 0 pi(c) = 1 pi(f#) = [0] usable rules: f(s(x)) -> s(f(f(x))) f(x) -> c(x,x) weight function: w0 = 1 w(f#) = w(c) = 1 w(f) = w(s) = 0 precedence: f# ~ c ~ f ~ s problem: DPs: TRS: f(s(x)) -> s(f(f(x))) f(x) -> c(x,x) Qed