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

Proof:
 Bounds Processor:
  bound: 2
  enrichment: match
  automaton:
   final states: {3,2}
   transitions:
    c1(10) -> 11*
    c1(11) -> 12*
    a1(9) -> 10*
    a1(8) -> 9*
    b1(6) -> 7*
    b2(20) -> 21*
    b2(22) -> 23*
    a0(1) -> 2*
    b0(1) -> 3*
    c0(1) -> 1*
    1 -> 6*
    6 -> 21,9,22
    7 -> 8,2
    8 -> 20*
    9 -> 22*
    12 -> 10,2
    20 -> 23*
    21 -> 9*
    23 -> 10*
  problem:
   
  Qed