YES Problem: r(e(x1)) -> w(r(x1)) i(t(x1)) -> e(r(x1)) e(w(x1)) -> r(i(x1)) t(e(x1)) -> r(e(x1)) w(r(x1)) -> i(t(x1)) e(r(x1)) -> e(w(x1)) r(i(t(e(r(x1))))) -> e(w(r(i(t(e(x1)))))) Proof: Arctic Interpretation Processor: dimension: 1 interpretation: [i](x0) = x0, [t](x0) = 3x0, [w](x0) = 1x0, [r](x0) = 2x0, [e](x0) = 1x0 orientation: r(e(x1)) = 3x1 >= 3x1 = w(r(x1)) i(t(x1)) = 3x1 >= 3x1 = e(r(x1)) e(w(x1)) = 2x1 >= 2x1 = r(i(x1)) t(e(x1)) = 4x1 >= 3x1 = r(e(x1)) w(r(x1)) = 3x1 >= 3x1 = i(t(x1)) e(r(x1)) = 3x1 >= 2x1 = e(w(x1)) r(i(t(e(r(x1))))) = 8x1 >= 8x1 = e(w(r(i(t(e(x1)))))) problem: r(e(x1)) -> w(r(x1)) i(t(x1)) -> e(r(x1)) e(w(x1)) -> r(i(x1)) w(r(x1)) -> i(t(x1)) r(i(t(e(r(x1))))) -> e(w(r(i(t(e(x1)))))) String Reversal Processor: e(r(x1)) -> r(w(x1)) t(i(x1)) -> r(e(x1)) w(e(x1)) -> i(r(x1)) r(w(x1)) -> t(i(x1)) r(e(t(i(r(x1))))) -> e(t(i(r(w(e(x1)))))) Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [i](x0) = [0 0 0]x0 [0 1 0] , [1 0 1] [0] [t](x0) = [0 0 0]x0 + [1] [0 0 0] [0], [1 1 0] [0] [w](x0) = [0 0 0]x0 + [0] [1 0 0] [1], [1 1 0] [0] [r](x0) = [0 0 0]x0 + [1] [0 0 0] [0], [1 0 0] [e](x0) = [0 1 0]x0 [0 0 0] orientation: [1 1 0] [0] [1 1 0] [0] e(r(x1)) = [0 0 0]x1 + [1] >= [0 0 0]x1 + [1] = r(w(x1)) [0 0 0] [0] [0 0 0] [0] [1 1 0] [0] [1 1 0] [0] t(i(x1)) = [0 0 0]x1 + [1] >= [0 0 0]x1 + [1] = r(e(x1)) [0 0 0] [0] [0 0 0] [0] [1 1 0] [0] [1 1 0] [0] w(e(x1)) = [0 0 0]x1 + [0] >= [0 0 0]x1 + [0] = i(r(x1)) [1 0 0] [1] [0 0 0] [1] [1 1 0] [0] [1 1 0] [0] r(w(x1)) = [0 0 0]x1 + [1] >= [0 0 0]x1 + [1] = t(i(x1)) [0 0 0] [0] [0 0 0] [0] [1 1 0] [2] [1 1 0] [1] r(e(t(i(r(x1))))) = [0 0 0]x1 + [1] >= [0 0 0]x1 + [1] = e(t(i(r(w(e(x1)))))) [0 0 0] [0] [0 0 0] [0] problem: e(r(x1)) -> r(w(x1)) t(i(x1)) -> r(e(x1)) w(e(x1)) -> i(r(x1)) r(w(x1)) -> t(i(x1)) Arctic Interpretation Processor: dimension: 2 interpretation: [0 -&] [i](x0) = [-& 1 ]x0, [0 1] [t](x0) = [2 2]x0, [1 -&] [w](x0) = [1 2 ]x0, [0 0] [r](x0) = [0 1]x0, [0 1] [e](x0) = [0 2]x0 orientation: [1 2] [1 2] e(r(x1)) = [2 3]x1 >= [2 3]x1 = r(w(x1)) [0 2] [0 2] t(i(x1)) = [2 3]x1 >= [1 3]x1 = r(e(x1)) [1 2] [0 0] w(e(x1)) = [2 4]x1 >= [1 2]x1 = i(r(x1)) [1 2] [0 2] r(w(x1)) = [2 3]x1 >= [2 3]x1 = t(i(x1)) problem: e(r(x1)) -> r(w(x1)) t(i(x1)) -> r(e(x1)) r(w(x1)) -> t(i(x1)) String Reversal Processor: r(e(x1)) -> w(r(x1)) i(t(x1)) -> e(r(x1)) w(r(x1)) -> i(t(x1)) Bounds Processor: bound: 2 enrichment: match automaton: final states: {5,4,1} transitions: i1(17) -> 18* t1(16) -> 17* e1(8) -> 9* r1(7) -> 8* e2(20) -> 21* r2(19) -> 20* f50() -> 2* w0(3) -> 1* r0(2) -> 3* e0(3) -> 4* i0(6) -> 5* t0(2) -> 6* 1 -> 20,3,8 2 -> 16,7 9 -> 5* 16 -> 19* 18 -> 1* 21 -> 18,1 problem: Qed