YES Problem: C(x1) -> c(x1) c(c(x1)) -> x1 b(b(x1)) -> B(x1) B(B(x1)) -> b(x1) c(B(c(b(c(x1))))) -> B(c(b(c(B(c(b(x1))))))) b(B(x1)) -> x1 B(b(x1)) -> x1 c(C(x1)) -> x1 C(c(x1)) -> x1 Proof: Matrix Interpretation Processor: dim=1 interpretation: [c](x0) = 2x0, [B](x0) = x0, [C](x0) = 4x0 + 8, [b](x0) = x0 orientation: C(x1) = 4x1 + 8 >= 2x1 = c(x1) c(c(x1)) = 4x1 >= x1 = x1 b(b(x1)) = x1 >= x1 = B(x1) B(B(x1)) = x1 >= x1 = b(x1) c(B(c(b(c(x1))))) = 8x1 >= 8x1 = B(c(b(c(B(c(b(x1))))))) b(B(x1)) = x1 >= x1 = x1 B(b(x1)) = x1 >= x1 = x1 c(C(x1)) = 8x1 + 16 >= x1 = x1 C(c(x1)) = 8x1 + 8 >= x1 = x1 problem: c(c(x1)) -> x1 b(b(x1)) -> B(x1) B(B(x1)) -> b(x1) c(B(c(b(c(x1))))) -> B(c(b(c(B(c(b(x1))))))) b(B(x1)) -> x1 B(b(x1)) -> x1 String Reversal Processor: c(c(x1)) -> x1 b(b(x1)) -> B(x1) B(B(x1)) -> b(x1) c(b(c(B(c(x1))))) -> b(c(B(c(b(c(B(x1))))))) B(b(x1)) -> x1 b(B(x1)) -> x1 Matrix Interpretation Processor: dim=1 interpretation: [c](x0) = x0 + 1, [B](x0) = x0, [b](x0) = x0 orientation: c(c(x1)) = x1 + 2 >= x1 = x1 b(b(x1)) = x1 >= x1 = B(x1) B(B(x1)) = x1 >= x1 = b(x1) c(b(c(B(c(x1))))) = x1 + 3 >= x1 + 3 = b(c(B(c(b(c(B(x1))))))) B(b(x1)) = x1 >= x1 = x1 b(B(x1)) = x1 >= x1 = x1 problem: b(b(x1)) -> B(x1) B(B(x1)) -> b(x1) c(b(c(B(c(x1))))) -> b(c(B(c(b(c(B(x1))))))) B(b(x1)) -> x1 b(B(x1)) -> x1 Bounds Processor: bound: 1 enrichment: match automaton: final states: {2,4,3,1} transitions: B0(7) -> 8* B0(2) -> 1* c0(1) -> 5* c0(6) -> 7* c0(8) -> 9* b0(2) -> 3* b0(5) -> 6* b0(9) -> 4* f40() -> 2* B1(10) -> 11* 4 -> 5,7 11 -> 6* 2 -> 1* 1 -> 3* 9 -> 10,8 3 -> 1* problem: Qed