YES(?,O(n^1))

Problem:
 p(p(b(a(x0)),x1),p(x2,x3)) -> p(p(x3,a(x2)),p(b(a(x1)),b(x0)))

Proof:
 Bounds Processor:
  bound: 0
  enrichment: match
  automaton:
   final states: {3}
   transitions:
    p0(1,2) -> 3*
    p0(2,1) -> 3*
    p0(1,1) -> 3*
    p0(2,2) -> 3*
    b0(2) -> 1*
    b0(1) -> 1*
    a0(2) -> 2*
    a0(1) -> 2*
  problem:
   
  Qed