YES

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

Proof:
 Bounds Processor:
  bound: 2
  enrichment: match
  automaton:
   final states: {2,1}
   transitions:
    a2(50) -> 51*
    a2(51) -> 52*
    a2(47) -> 48*
    a2(53) -> 54*
    a2(44) -> 45*
    b0(2) -> 1*
    b0(1) -> 1*
    b2(46) -> 47*
    b2(48) -> 49*
    b2(52) -> 53*
    b2(45) -> 46*
    b2(49) -> 50*
    a0(2) -> 2*
    a0(1) -> 2*
    b1(40) -> 41*
    b1(42) -> 43*
    b1(6) -> 7*
    b1(12) -> 13*
    b1(8) -> 9*
    b1(9) -> 10*
    b1(5) -> 6*
    a1(10) -> 11*
    a1(7) -> 8*
    a1(4) -> 5*
    a1(13) -> 14*
    a1(36) -> 37*
    a1(11) -> 12*
    43 -> 7*
    7 -> 40*
    14 -> 9,6,1
    11 -> 44*
    2 -> 4*
    54 -> 9*
    13 -> 42*
    1 -> 36*
    37 -> 5*
    41 -> 7*
  problem:
   
  Qed