YES Problem: r(r(x1)) -> s(r(x1)) r(s(x1)) -> s(r(x1)) r(n(x1)) -> s(r(x1)) r(b(x1)) -> u(s(b(x1))) r(u(x1)) -> u(r(x1)) s(u(x1)) -> u(s(x1)) n(u(x1)) -> u(n(x1)) t(r(u(x1))) -> t(c(r(x1))) t(s(u(x1))) -> t(c(r(x1))) t(n(u(x1))) -> t(c(r(x1))) c(u(x1)) -> u(c(x1)) c(s(x1)) -> s(c(x1)) c(r(x1)) -> r(c(x1)) c(n(x1)) -> n(c(x1)) c(n(x1)) -> n(x1) Proof: Matrix Interpretation Processor: dim=1 interpretation: [u](x0) = 4x0 + 1, [s](x0) = x0, [b](x0) = 4x0 + 4, [t](x0) = x0 + 4, [r](x0) = 4x0 + 1, [c](x0) = x0, [n](x0) = 4x0 orientation: r(r(x1)) = 16x1 + 5 >= 4x1 + 1 = s(r(x1)) r(s(x1)) = 4x1 + 1 >= 4x1 + 1 = s(r(x1)) r(n(x1)) = 16x1 + 1 >= 4x1 + 1 = s(r(x1)) r(b(x1)) = 16x1 + 17 >= 16x1 + 17 = u(s(b(x1))) r(u(x1)) = 16x1 + 5 >= 16x1 + 5 = u(r(x1)) s(u(x1)) = 4x1 + 1 >= 4x1 + 1 = u(s(x1)) n(u(x1)) = 16x1 + 4 >= 16x1 + 1 = u(n(x1)) t(r(u(x1))) = 16x1 + 9 >= 4x1 + 5 = t(c(r(x1))) t(s(u(x1))) = 4x1 + 5 >= 4x1 + 5 = t(c(r(x1))) t(n(u(x1))) = 16x1 + 8 >= 4x1 + 5 = t(c(r(x1))) c(u(x1)) = 4x1 + 1 >= 4x1 + 1 = u(c(x1)) c(s(x1)) = x1 >= x1 = s(c(x1)) c(r(x1)) = 4x1 + 1 >= 4x1 + 1 = r(c(x1)) c(n(x1)) = 4x1 >= 4x1 = n(c(x1)) c(n(x1)) = 4x1 >= 4x1 = n(x1) problem: r(s(x1)) -> s(r(x1)) r(n(x1)) -> s(r(x1)) r(b(x1)) -> u(s(b(x1))) r(u(x1)) -> u(r(x1)) s(u(x1)) -> u(s(x1)) t(s(u(x1))) -> t(c(r(x1))) c(u(x1)) -> u(c(x1)) c(s(x1)) -> s(c(x1)) c(r(x1)) -> r(c(x1)) c(n(x1)) -> n(c(x1)) c(n(x1)) -> n(x1) Matrix Interpretation Processor: dim=1 interpretation: [u](x0) = 2x0 + 10, [s](x0) = x0, [b](x0) = 8x0 + 3, [t](x0) = x0 + 5, [r](x0) = 2x0 + 10, [c](x0) = x0, [n](x0) = x0 + 2 orientation: r(s(x1)) = 2x1 + 10 >= 2x1 + 10 = s(r(x1)) r(n(x1)) = 2x1 + 14 >= 2x1 + 10 = s(r(x1)) r(b(x1)) = 16x1 + 16 >= 16x1 + 16 = u(s(b(x1))) r(u(x1)) = 4x1 + 30 >= 4x1 + 30 = u(r(x1)) s(u(x1)) = 2x1 + 10 >= 2x1 + 10 = u(s(x1)) t(s(u(x1))) = 2x1 + 15 >= 2x1 + 15 = t(c(r(x1))) c(u(x1)) = 2x1 + 10 >= 2x1 + 10 = u(c(x1)) c(s(x1)) = x1 >= x1 = s(c(x1)) c(r(x1)) = 2x1 + 10 >= 2x1 + 10 = r(c(x1)) c(n(x1)) = x1 + 2 >= x1 + 2 = n(c(x1)) c(n(x1)) = x1 + 2 >= x1 + 2 = n(x1) problem: r(s(x1)) -> s(r(x1)) r(b(x1)) -> u(s(b(x1))) r(u(x1)) -> u(r(x1)) s(u(x1)) -> u(s(x1)) t(s(u(x1))) -> t(c(r(x1))) c(u(x1)) -> u(c(x1)) c(s(x1)) -> s(c(x1)) c(r(x1)) -> r(c(x1)) c(n(x1)) -> n(c(x1)) c(n(x1)) -> n(x1) String Reversal Processor: s(r(x1)) -> r(s(x1)) b(r(x1)) -> b(s(u(x1))) u(r(x1)) -> r(u(x1)) u(s(x1)) -> s(u(x1)) u(s(t(x1))) -> r(c(t(x1))) u(c(x1)) -> c(u(x1)) s(c(x1)) -> c(s(x1)) r(c(x1)) -> c(r(x1)) n(c(x1)) -> c(n(x1)) n(c(x1)) -> n(x1) Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [u](x0) = [0 1 0]x0 [1 1 1] , [1 1 0] [s](x0) = [0 0 0]x0 [0 0 1] , [1 1 1] [b](x0) = [0 0 0]x0 [0 0 0] , [1 0 0] [0] [t](x0) = [0 0 0]x0 + [0] [1 0 1] [1], [1 0 0] [0] [r](x0) = [0 1 0]x0 + [0] [1 1 1] [1], [1 0 0] [c](x0) = [0 1 0]x0 [0 0 0] , [1 0 0] [0] [n](x0) = [0 0 0]x0 + [1] [0 0 0] [0] orientation: [1 1 0] [0] [1 1 0] [0] s(r(x1)) = [0 0 0]x1 + [0] >= [0 0 0]x1 + [0] = r(s(x1)) [1 1 1] [1] [1 1 1] [1] [2 2 1] [1] [2 2 1] b(r(x1)) = [0 0 0]x1 + [0] >= [0 0 0]x1 = b(s(u(x1))) [0 0 0] [0] [0 0 0] [1 0 0] [0] [1 0 0] [0] u(r(x1)) = [0 1 0]x1 + [0] >= [0 1 0]x1 + [0] = r(u(x1)) [2 2 1] [1] [2 2 1] [1] [1 1 0] [1 1 0] u(s(x1)) = [0 0 0]x1 >= [0 0 0]x1 = s(u(x1)) [1 1 1] [1 1 1] [1 0 0] [0] [1 0 0] [0] u(s(t(x1))) = [0 0 0]x1 + [0] >= [0 0 0]x1 + [0] = r(c(t(x1))) [2 0 1] [1] [1 0 0] [1] [1 0 0] [1 0 0] u(c(x1)) = [0 1 0]x1 >= [0 1 0]x1 = c(u(x1)) [1 1 0] [0 0 0] [1 1 0] [1 1 0] s(c(x1)) = [0 0 0]x1 >= [0 0 0]x1 = c(s(x1)) [0 0 0] [0 0 0] [1 0 0] [0] [1 0 0] r(c(x1)) = [0 1 0]x1 + [0] >= [0 1 0]x1 = c(r(x1)) [1 1 0] [1] [0 0 0] [1 0 0] [0] [1 0 0] [0] n(c(x1)) = [0 0 0]x1 + [1] >= [0 0 0]x1 + [1] = c(n(x1)) [0 0 0] [0] [0 0 0] [0] [1 0 0] [0] [1 0 0] [0] n(c(x1)) = [0 0 0]x1 + [1] >= [0 0 0]x1 + [1] = n(x1) [0 0 0] [0] [0 0 0] [0] problem: s(r(x1)) -> r(s(x1)) u(r(x1)) -> r(u(x1)) u(s(x1)) -> s(u(x1)) u(s(t(x1))) -> r(c(t(x1))) u(c(x1)) -> c(u(x1)) s(c(x1)) -> c(s(x1)) r(c(x1)) -> c(r(x1)) n(c(x1)) -> c(n(x1)) n(c(x1)) -> n(x1) KBO Processor: weight function: w0 = 1 w(c) = w(t) = w(u) = w(s) = w(r) = 1 w(n) = 0 precedence: n > t > u > s > r > c problem: Qed