YES Problem: strict: b(b(x1)) -> c(d(x1)) c(c(x1)) -> d(d(d(x1))) d(d(d(x1))) -> a(c(x1)) weak: a(a(x1)) -> b(c(x1)) b(c(x1)) -> a(a(x1)) Proof: Arctic Interpretation Processor: dimension: 1 interpretation: [d](x0) = 2x0, [a](x0) = 3x0, [b](x0) = 3x0, [c](x0) = 3x0 orientation: b(b(x1)) = 6x1 >= 5x1 = c(d(x1)) c(c(x1)) = 6x1 >= 6x1 = d(d(d(x1))) d(d(d(x1))) = 6x1 >= 6x1 = a(c(x1)) a(a(x1)) = 6x1 >= 6x1 = b(c(x1)) b(c(x1)) = 6x1 >= 6x1 = a(a(x1)) problem: strict: c(c(x1)) -> d(d(d(x1))) d(d(d(x1))) -> a(c(x1)) weak: a(a(x1)) -> b(c(x1)) b(c(x1)) -> a(a(x1)) String Reversal Processor: strict: c(c(x1)) -> d(d(d(x1))) d(d(d(x1))) -> c(a(x1)) weak: a(a(x1)) -> c(b(x1)) c(b(x1)) -> a(a(x1)) Arctic Interpretation Processor: dimension: 1 interpretation: [d](x0) = 4x0, [a](x0) = 4x0, [b](x0) = x0, [c](x0) = 8x0 orientation: c(c(x1)) = 16x1 >= 12x1 = d(d(d(x1))) d(d(d(x1))) = 12x1 >= 12x1 = c(a(x1)) a(a(x1)) = 8x1 >= 8x1 = c(b(x1)) c(b(x1)) = 8x1 >= 8x1 = a(a(x1)) problem: strict: d(d(d(x1))) -> c(a(x1)) weak: a(a(x1)) -> c(b(x1)) c(b(x1)) -> a(a(x1)) Arctic Interpretation Processor: dimension: 1 interpretation: [d](x0) = 1x0, [a](x0) = x0, [b](x0) = x0, [c](x0) = x0 orientation: d(d(d(x1))) = 3x1 >= x1 = c(a(x1)) a(a(x1)) = x1 >= x1 = c(b(x1)) c(b(x1)) = x1 >= x1 = a(a(x1)) problem: strict: weak: a(a(x1)) -> c(b(x1)) c(b(x1)) -> a(a(x1)) Qed