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

Proof:
 Bounds Processor:
  bound: 2
  enrichment: match
  automaton:
   final states: {3,2}
   transitions:
    c1(10) -> 11*
    c1(8) -> 9*
    a1(9) -> 10*
    b2(20) -> 21*
    b2(19) -> 20*
    b2(18) -> 19*
    a2(17) -> 18*
    a0(1) -> 2*
    b0(1) -> 1*
    c0(1) -> 3*
    1 -> 8,2
    8 -> 17*
    9 -> 10*
    11 -> 18,2
    17 -> 18*
    21 -> 11,2
  problem:
   
  Qed