YES

Problem:
 b(a(a(b(a(b(x1)))))) -> a(b(a(b(a(b(a(x1)))))))

Proof:
 Bounds Processor:
  bound: 3
  enrichment: match
  automaton:
   final states: {3}
   transitions:
    a2(34) -> 35*
    a2(30) -> 31*
    a2(62) -> 63*
    a2(32) -> 33*
    a2(28) -> 29*
    a2(56) -> 57*
    a2(60) -> 61*
    a2(58) -> 59*
    a2(38) -> 39*
    a2(66) -> 67*
    b0(3) -> 3*
    a3(72) -> 73*
    a3(78) -> 79*
    a3(74) -> 75*
    a3(76) -> 77*
    b2(33) -> 34*
    b2(31) -> 32*
    b2(59) -> 60*
    b2(57) -> 58*
    b2(29) -> 30*
    b2(61) -> 62*
    a0(3) -> 3*
    b1(13) -> 14*
    b1(15) -> 16*
    b1(17) -> 18*
    a1(70) -> 71*
    a1(18) -> 19*
    a1(14) -> 15*
    a1(12) -> 13*
    a1(26) -> 27*
    a1(20) -> 21*
    a1(16) -> 17*
    b3(75) -> 76*
    b3(77) -> 78*
    b3(73) -> 74*
    27 -> 13*
    19 -> 30,14,3
    17 -> 26*
    35 -> 32,16,14
    63 -> 18,16
    67 -> 57*
    21 -> 13*
    79 -> 34*
    13 -> 38*
    71 -> 13*
    31 -> 72,56
    59 -> 70,66
    3 -> 12*
    39 -> 29*
    15 -> 28,20
  problem:
   
  Qed