YES Problem: a(b(x)) -> b(a(a(x))) b(c(x)) -> c(b(b(x))) c(a(x)) -> a(c(c(x))) u(a(x)) -> x v(b(x)) -> x w(c(x)) -> x a(u(x)) -> x b(v(x)) -> x c(w(x)) -> x Proof: String Reversal Processor: b(a(x)) -> a(a(b(x))) c(b(x)) -> b(b(c(x))) a(c(x)) -> c(c(a(x))) a(u(x)) -> x b(v(x)) -> x c(w(x)) -> x u(a(x)) -> x v(b(x)) -> x w(c(x)) -> x Matrix Interpretation Processor: dim=1 interpretation: [v](x0) = x0 + 7, [a](x0) = x0, [u](x0) = x0 + 1, [w](x0) = 8x0 + 6, [b](x0) = x0, [c](x0) = x0 orientation: b(a(x)) = x >= x = a(a(b(x))) c(b(x)) = x >= x = b(b(c(x))) a(c(x)) = x >= x = c(c(a(x))) a(u(x)) = x + 1 >= x = x b(v(x)) = x + 7 >= x = x c(w(x)) = 8x + 6 >= x = x u(a(x)) = x + 1 >= x = x v(b(x)) = x + 7 >= x = x w(c(x)) = 8x + 6 >= x = x problem: b(a(x)) -> a(a(b(x))) c(b(x)) -> b(b(c(x))) a(c(x)) -> c(c(a(x))) Bounds Processor: bound: 0 enrichment: match automaton: final states: {8,5,1} transitions: a0(3) -> 4* a0(4) -> 1* a0(2) -> 9* f60() -> 2* b0(2) -> 3* b0(6) -> 7* b0(7) -> 5* c0(2) -> 6* c0(10) -> 8* c0(9) -> 10* 8 -> 9* 1 -> 3* 5 -> 6* problem: Qed