YES Problem: a(a(b(b(x1)))) -> b(b(b(a(a(a(x1)))))) Proof: String Reversal Processor: b(b(a(a(x1)))) -> a(a(a(b(b(b(x1)))))) Bounds Processor: bound: 3 enrichment: match automaton: final states: {1} transitions: a1(32) -> 33* a1(12) -> 13* a1(34) -> 35* a1(11) -> 12* a1(33) -> 34* a1(13) -> 14* b1(30) -> 31* b1(10) -> 11* b1(29) -> 30* b1(9) -> 10* b1(31) -> 32* b1(8) -> 9* a2(60) -> 61* a2(40) -> 41* a2(62) -> 63* a2(39) -> 40* a2(61) -> 62* a2(41) -> 42* b2(57) -> 58* b2(37) -> 38* b2(59) -> 60* b2(36) -> 37* b2(58) -> 59* b2(38) -> 39* f20() -> 2* a3(67) -> 68* a3(69) -> 70* a3(68) -> 69* a0(5) -> 6* a0(7) -> 1* a0(6) -> 7* b3(65) -> 66* b3(64) -> 65* b3(66) -> 67* b0(2) -> 3* b0(4) -> 5* b0(3) -> 4* 1 -> 3,4 6 -> 8* 11 -> 36* 13 -> 29* 14 -> 5* 33 -> 57* 35 -> 10* 42 -> 31* 61 -> 64* 63 -> 37* 70 -> 39* problem: Qed