YES Problem: t(f(x1)) -> t(c(n(x1))) n(f(x1)) -> f(n(x1)) o(f(x1)) -> f(o(x1)) n(s(x1)) -> f(s(x1)) o(s(x1)) -> f(s(x1)) c(f(x1)) -> f(c(x1)) c(n(x1)) -> n(c(x1)) c(o(x1)) -> o(c(x1)) c(o(x1)) -> o(x1) Proof: Arctic Interpretation Processor: dimension: 1 interpretation: [s](x0) = 3x0, [o](x0) = 5x0, [c](x0) = x0, [n](x0) = x0, [t](x0) = x0, [f](x0) = x0 orientation: t(f(x1)) = x1 >= x1 = t(c(n(x1))) n(f(x1)) = x1 >= x1 = f(n(x1)) o(f(x1)) = 5x1 >= 5x1 = f(o(x1)) n(s(x1)) = 3x1 >= 3x1 = f(s(x1)) o(s(x1)) = 8x1 >= 3x1 = f(s(x1)) c(f(x1)) = x1 >= x1 = f(c(x1)) c(n(x1)) = x1 >= x1 = n(c(x1)) c(o(x1)) = 5x1 >= 5x1 = o(c(x1)) c(o(x1)) = 5x1 >= 5x1 = o(x1) problem: t(f(x1)) -> t(c(n(x1))) n(f(x1)) -> f(n(x1)) o(f(x1)) -> f(o(x1)) n(s(x1)) -> f(s(x1)) c(f(x1)) -> f(c(x1)) c(n(x1)) -> n(c(x1)) c(o(x1)) -> o(c(x1)) c(o(x1)) -> o(x1) Matrix Interpretation Processor: dim=1 interpretation: [s](x0) = 4x0 + 3, [o](x0) = 4x0, [c](x0) = x0, [n](x0) = 4x0 + 1, [t](x0) = x0 + 8, [f](x0) = 4x0 + 1 orientation: t(f(x1)) = 4x1 + 9 >= 4x1 + 9 = t(c(n(x1))) n(f(x1)) = 16x1 + 5 >= 16x1 + 5 = f(n(x1)) o(f(x1)) = 16x1 + 4 >= 16x1 + 1 = f(o(x1)) n(s(x1)) = 16x1 + 13 >= 16x1 + 13 = f(s(x1)) c(f(x1)) = 4x1 + 1 >= 4x1 + 1 = f(c(x1)) c(n(x1)) = 4x1 + 1 >= 4x1 + 1 = n(c(x1)) c(o(x1)) = 4x1 >= 4x1 = o(c(x1)) c(o(x1)) = 4x1 >= 4x1 = o(x1) problem: t(f(x1)) -> t(c(n(x1))) n(f(x1)) -> f(n(x1)) n(s(x1)) -> f(s(x1)) c(f(x1)) -> f(c(x1)) c(n(x1)) -> n(c(x1)) c(o(x1)) -> o(c(x1)) c(o(x1)) -> o(x1) String Reversal Processor: f(t(x1)) -> n(c(t(x1))) f(n(x1)) -> n(f(x1)) s(n(x1)) -> s(f(x1)) f(c(x1)) -> c(f(x1)) n(c(x1)) -> c(n(x1)) o(c(x1)) -> c(o(x1)) o(c(x1)) -> o(x1) Matrix Interpretation Processor: dim=3 interpretation: [1 1 1] [1] [s](x0) = [0 1 1]x0 + [0] [0 0 0] [0], [1 0 0] [o](x0) = [0 0 0]x0 [1 0 0] , [1 0 0] [c](x0) = [0 0 0]x0 [0 0 0] , [1 0 0] [0] [n](x0) = [0 0 1]x0 + [1] [0 0 1] [1], [1 1 0] [0] [t](x0) = [0 0 0]x0 + [0] [0 0 0] [1], [1 0 0] [1] [f](x0) = [0 0 1]x0 + [0] [0 0 1] [0] orientation: [1 1 0] [1] [1 1 0] [0] f(t(x1)) = [0 0 0]x1 + [1] >= [0 0 0]x1 + [1] = n(c(t(x1))) [0 0 0] [1] [0 0 0] [1] [1 0 0] [1] [1 0 0] [1] f(n(x1)) = [0 0 1]x1 + [1] >= [0 0 1]x1 + [1] = n(f(x1)) [0 0 1] [1] [0 0 1] [1] [1 0 2] [3] [1 0 2] [2] s(n(x1)) = [0 0 2]x1 + [2] >= [0 0 2]x1 + [0] = s(f(x1)) [0 0 0] [0] [0 0 0] [0] [1 0 0] [1] [1 0 0] [1] f(c(x1)) = [0 0 0]x1 + [0] >= [0 0 0]x1 + [0] = c(f(x1)) [0 0 0] [0] [0 0 0] [0] [1 0 0] [0] [1 0 0] n(c(x1)) = [0 0 0]x1 + [1] >= [0 0 0]x1 = c(n(x1)) [0 0 0] [1] [0 0 0] [1 0 0] [1 0 0] o(c(x1)) = [0 0 0]x1 >= [0 0 0]x1 = c(o(x1)) [1 0 0] [0 0 0] [1 0 0] [1 0 0] o(c(x1)) = [0 0 0]x1 >= [0 0 0]x1 = o(x1) [1 0 0] [1 0 0] problem: f(n(x1)) -> n(f(x1)) f(c(x1)) -> c(f(x1)) n(c(x1)) -> c(n(x1)) o(c(x1)) -> c(o(x1)) o(c(x1)) -> o(x1) Arctic Interpretation Processor: dimension: 2 interpretation: [0 -&] [o](x0) = [2 0 ]x0, [3 1 ] [c](x0) = [-& 3 ]x0, [0 1] [n](x0) = [0 0]x0, [0 2] [f](x0) = [1 0]x0 orientation: [2 2] [2 2] f(n(x1)) = [1 2]x1 >= [1 2]x1 = n(f(x1)) [3 5] [3 5] f(c(x1)) = [4 3]x1 >= [4 3]x1 = c(f(x1)) [3 4] [3 4] n(c(x1)) = [3 3]x1 >= [3 3]x1 = c(n(x1)) [3 1] [3 1] o(c(x1)) = [5 3]x1 >= [5 3]x1 = c(o(x1)) [3 1] [0 -&] o(c(x1)) = [5 3]x1 >= [2 0 ]x1 = o(x1) problem: f(n(x1)) -> n(f(x1)) f(c(x1)) -> c(f(x1)) n(c(x1)) -> c(n(x1)) o(c(x1)) -> c(o(x1)) KBO Processor: weight function: w0 = 1 w(o) = w(c) = w(n) = w(f) = 1 precedence: f > o ~ n > c problem: Qed