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

Proof:
 Bounds Processor:
  bound: 2
  enrichment: match
  automaton:
   final states: {3,2}
   transitions:
    b1(14) -> 15*
    b1(6) -> 7*
    c1(5) -> 6*
    a1(4) -> 5*
    b2(16) -> 17*
    a0(1) -> 2*
    b0(1) -> 1*
    c0(1) -> 3*
    1 -> 14,4,2
    4 -> 5*
    5 -> 16*
    7 -> 5,2
    15 -> 3*
    17 -> 6*
  problem:
   
  Qed