YES Problem: a(x1) -> b(x1) a(b(x1)) -> b(c(a(x1))) b(x1) -> c(x1) c(b(x1)) -> a(x1) Proof: Arctic Interpretation Processor: dimension: 2 interpretation: [0 0 ] [c](x0) = [-& 0 ]x0, [1 1 ] [b](x0) = [-& 1 ]x0, [1 1 ] [a](x0) = [-& 1 ]x0 orientation: [1 1 ] [1 1 ] a(x1) = [-& 1 ]x1 >= [-& 1 ]x1 = b(x1) [2 2 ] [2 2 ] a(b(x1)) = [-& 2 ]x1 >= [-& 2 ]x1 = b(c(a(x1))) [1 1 ] [0 0 ] b(x1) = [-& 1 ]x1 >= [-& 0 ]x1 = c(x1) [1 1 ] [1 1 ] c(b(x1)) = [-& 1 ]x1 >= [-& 1 ]x1 = a(x1) problem: a(x1) -> b(x1) a(b(x1)) -> b(c(a(x1))) c(b(x1)) -> a(x1) KBO Processor: weight function: w0 = 1 w(b) = w(a) = 1 w(c) = 0 precedence: c > a > b problem: Qed