YES Problem: b(c(b(c(a(a(x1)))))) -> a(a(a(b(c(b(c(b(c(x1))))))))) Proof: String Reversal Processor: a(a(c(b(c(b(x1)))))) -> c(b(c(b(c(b(a(a(a(x1))))))))) Bounds Processor: bound: 5 enrichment: match automaton: final states: {4} transitions: b3(172) -> 173* b3(112) -> 113* b3(102) -> 103* b3(114) -> 115* b3(104) -> 105* b3(146) -> 147* b3(168) -> 169* b3(148) -> 149* b3(170) -> 171* b3(150) -> 151* b3(110) -> 111* b3(100) -> 101* a3(167) -> 168* a3(137) -> 138* a3(107) -> 108* a3(97) -> 98* a3(144) -> 145* a3(109) -> 110* a3(99) -> 100* a3(251) -> 252* a3(166) -> 167* a3(143) -> 144* a3(108) -> 109* a3(98) -> 99* a3(205) -> 206* a3(165) -> 166* a3(145) -> 146* c4(277) -> 278* c4(299) -> 300* c4(279) -> 280* c4(189) -> 190* c4(179) -> 180* c4(301) -> 302* c4(281) -> 282* c4(231) -> 232* c4(191) -> 192* c4(181) -> 182* c4(303) -> 304* c4(233) -> 234* c4(193) -> 194* c4(183) -> 184* c4(235) -> 236* b4(232) -> 233* b4(192) -> 193* b4(182) -> 183* b4(234) -> 235* b4(276) -> 277* b4(298) -> 299* b4(278) -> 279* b4(188) -> 189* b4(178) -> 179* b4(300) -> 301* b4(280) -> 281* b4(230) -> 231* b4(190) -> 191* b4(180) -> 181* b4(302) -> 303* a0(4) -> 4* a4(227) -> 228* a4(187) -> 188* a4(177) -> 178* a4(274) -> 275* a4(229) -> 230* a4(296) -> 297* a4(186) -> 187* a4(176) -> 177* a4(273) -> 274* a4(228) -> 229* a4(295) -> 296* a4(275) -> 276* a4(185) -> 186* a4(175) -> 176* a4(297) -> 298* c0(4) -> 4* c5(247) -> 248* c5(309) -> 310* c5(249) -> 250* c5(311) -> 312* c5(313) -> 314* c5(245) -> 246* b0(4) -> 4* b5(244) -> 245* b5(246) -> 247* b5(308) -> 309* b5(248) -> 249* b5(310) -> 311* b5(312) -> 313* c1(19) -> 20* c1(21) -> 22* c1(23) -> 24* a5(242) -> 243* a5(306) -> 307* a5(241) -> 242* a5(243) -> 244* a5(305) -> 306* a5(307) -> 308* b1(20) -> 21* b1(22) -> 23* b1(18) -> 19* a1(65) -> 66* a1(15) -> 16* a1(17) -> 18* a1(39) -> 40* a1(16) -> 17* a1(63) -> 64* c2(75) -> 76* c2(77) -> 78* c2(79) -> 80* c2(29) -> 30* c2(31) -> 32* c2(33) -> 34* b2(30) -> 31* b2(32) -> 33* b2(74) -> 75* b2(76) -> 77* b2(78) -> 79* b2(28) -> 29* a2(25) -> 26* a2(72) -> 73* a2(67) -> 68* a2(27) -> 28* a2(71) -> 72* a2(26) -> 27* a2(93) -> 94* a2(73) -> 74* a2(95) -> 96* c3(147) -> 148* c3(169) -> 170* c3(149) -> 150* c3(171) -> 172* c3(151) -> 152* c3(111) -> 112* c3(101) -> 102* c3(173) -> 174* c3(113) -> 114* c3(103) -> 104* c3(115) -> 116* c3(105) -> 106* 4 -> 15* 18 -> 71* 20 -> 25* 22 -> 39* 24 -> 16,17,4 28 -> 137,93 30 -> 97,67,63 32 -> 95,65 34 -> 72,18,16,4,15,17 40 -> 26* 64 -> 16* 66 -> 16* 68 -> 26* 76 -> 107* 80 -> 27* 94 -> 26* 96 -> 72* 100 -> 175* 104 -> 165* 106 -> 74,73 112 -> 227,143 116 -> 72,138,98,94 138 -> 98* 146 -> 295* 148 -> 185* 150 -> 205* 152 -> 74,28,93,137 174 -> 109* 184 -> 167* 190 -> 273,251 194 -> 109,17,27,99 206 -> 186* 232 -> 241* 236 -> 100* 250 -> 177* 252 -> 108* 278 -> 305* 282 -> 176* 304 -> 187* 314 -> 178* problem: Qed