YES Problem: b(a(b(a(a(x1))))) -> a(a(b(b(a(b(a(b(a(x1))))))))) Proof: String Reversal Processor: a(a(b(a(b(x1))))) -> a(b(a(b(a(b(b(a(a(x1))))))))) Bounds Processor: bound: 1 enrichment: match automaton: final states: {1} transitions: a1(19) -> 20* a1(11) -> 12* a1(12) -> 13* a1(17) -> 18* a1(15) -> 16* b1(13) -> 14* b1(16) -> 17* b1(18) -> 19* b1(14) -> 15* f20() -> 2* b0(4) -> 5* b0(9) -> 10* b0(7) -> 8* b0(5) -> 6* a0(10) -> 1* a0(6) -> 7* a0(2) -> 3* a0(8) -> 9* a0(3) -> 4* 7 -> 11* 1 -> 3,4 20 -> 4* problem: Qed