YES Problem: a(a(a(b(b(x1))))) -> b(b(b(b(b(a(a(a(a(a(x1)))))))))) Proof: String Reversal Processor: b(b(a(a(a(x1))))) -> a(a(a(a(a(b(b(b(b(b(x1)))))))))) Bounds Processor: bound: 2 enrichment: match automaton: final states: {1} transitions: a1(40) -> 41* a1(30) -> 31* a1(43) -> 44* a1(39) -> 40* a1(32) -> 33* a1(72) -> 73* a1(42) -> 43* a1(31) -> 32* a1(74) -> 75* a1(28) -> 29* a1(73) -> 74* a1(76) -> 77* a1(29) -> 30* a1(41) -> 42* a1(75) -> 76* a2(119) -> 120* a2(116) -> 117* a2(120) -> 121* a2(85) -> 86* a2(127) -> 128* a2(129) -> 130* a2(130) -> 131* a2(118) -> 119* a2(83) -> 84* a2(87) -> 88* a2(86) -> 87* a2(84) -> 85* a2(131) -> 132* a2(128) -> 129* a2(117) -> 118* b1(68) -> 69* b1(67) -> 68* b1(69) -> 70* b1(36) -> 37* b1(71) -> 72* b1(35) -> 36* b1(27) -> 28* b1(34) -> 35* b1(25) -> 26* b1(38) -> 39* b1(26) -> 27* b1(24) -> 25* b1(23) -> 24* b1(70) -> 71* b1(37) -> 38* f20() -> 2* b0(3) -> 4* b0(4) -> 5* b0(6) -> 7* b0(2) -> 3* b0(5) -> 6* a0(10) -> 11* a0(7) -> 8* a0(9) -> 10* a0(8) -> 9* a0(11) -> 1* b2(122) -> 123* b2(115) -> 116* b2(80) -> 81* b2(111) -> 112* b2(113) -> 114* b2(82) -> 83* b2(79) -> 80* b2(125) -> 126* b2(112) -> 113* b2(78) -> 79* b2(123) -> 124* b2(81) -> 82* b2(126) -> 127* b2(124) -> 125* b2(114) -> 115* 43 -> 67* 74 -> 78* 132 -> 71* 30 -> 34* 77 -> 25* 118 -> 122* 88 -> 27* 121 -> 69* 44 -> 7* 40 -> 111* 1 -> 3,4 9 -> 23* 33 -> 5,6 problem: Qed