YES(?,O(n^1))

Problem:
 C(C(x1)) -> c(c(x1))
 c(c(c(c(x1)))) -> x1
 b(b(b(b(x1)))) -> B(B(x1))
 B(B(B(B(x1)))) -> b(b(x1))
 c(c(B(B(c(c(b(b(c(c(x1)))))))))) -> B(B(c(c(b(b(c(c(B(B(c(c(b(b(x1))))))))))))))
 b(b(B(B(x1)))) -> x1
 B(B(b(b(x1)))) -> x1
 c(c(C(C(x1)))) -> x1
 C(C(c(c(x1)))) -> x1

Proof:
 Bounds Processor:
  bound: 0
  enrichment: match
  automaton:
   final states: {5,4,3,2}
   transitions:
    C0(1) -> 2*
    c0(1) -> 3*
    b0(1) -> 4*
    B0(1) -> 5*
    f80() -> 1*
  problem:
   
  Qed