YES Problem: b(c(a(x1))) -> a(b(a(b(x1)))) b(x1) -> c(c(x1)) a(a(x1)) -> a(c(b(a(x1)))) Proof: String Reversal Processor: a(c(b(x1))) -> b(a(b(a(x1)))) b(x1) -> c(c(x1)) a(a(x1)) -> a(b(c(a(x1)))) Bounds Processor: bound: 3 enrichment: match automaton: final states: {4} transitions: a1(65) -> 66* a1(12) -> 13* a1(28) -> 29* a1(10) -> 11* a1(26) -> 27* a1(24) -> 25* c1(16) -> 17* c1(22) -> 23* c1(15) -> 16* b1(13) -> 14* b1(27) -> 28* b1(29) -> 30* b1(23) -> 24* b1(11) -> 12* a0(4) -> 4* c3(79) -> 80* c3(89) -> 90* c3(90) -> 91* c3(78) -> 79* b0(4) -> 4* c0(4) -> 4* a2(92) -> 93* a2(60) -> 61* a2(84) -> 85* a2(63) -> 64* a2(81) -> 82* c2(52) -> 53* c2(67) -> 68* c2(57) -> 58* c2(54) -> 55* c2(68) -> 69* c2(55) -> 56* c2(61) -> 62* c2(51) -> 52* c2(58) -> 59* c2(82) -> 83* c2(73) -> 74* b2(62) -> 63* b2(83) -> 84* 56 -> 12* 27 -> 67* 24 -> 60* 74 -> 52* 17 -> 4* 83 -> 89* 64 -> 66,11,22 30 -> 11,4,10,15,22 69 -> 28* 85 -> 27* 12 -> 81* 93 -> 61* 14 -> 11,22,4 66 -> 11* 28 -> 92* 4 -> 15,10 11 -> 54,22 53 -> 30,14,4 91 -> 84* 13 -> 51,26 62 -> 78* 59 -> 24* 80 -> 63* 29 -> 73,65 25 -> 11,22,4 23 -> 57* problem: Qed