YES Problem: a(b(a(a(b(b(x1)))))) -> a(a(b(a(b(b(a(x1))))))) Proof: String Reversal Processor: b(b(a(a(b(a(x1)))))) -> a(b(b(a(b(a(a(x1))))))) Bounds Processor: bound: 1 enrichment: match automaton: final states: {3} transitions: a1(15) -> 16* a1(12) -> 13* a1(18) -> 19* a1(13) -> 14* b1(20) -> 21* b1(17) -> 18* b1(14) -> 15* b1(16) -> 17* b0(3) -> 3* a0(3) -> 3* 3 -> 12* 13 -> 20* 19 -> 3* 21 -> 15* problem: Qed