YES(?,O(n^1))

Problem:
 .(1(),x) -> x
 .(x,1()) -> x
 .(i(x),x) -> 1()
 .(x,i(x)) -> 1()
 i(1()) -> 1()
 i(i(x)) -> x
 .(i(y),.(y,z)) -> z
 .(y,.(i(y),z)) -> z

Proof:
 Bounds Processor:
  bound: 1
  enrichment: match
  automaton:
   final states: {7,6,3,2}
   transitions:
    .0(6,6) -> 2*
    .0(1,6) -> 2*
    .0(7,1) -> 2*
    .0(7,7) -> 2*
    .0(6,1) -> 2*
    .0(1,1) -> 2*
    .0(6,7) -> 2*
    .0(1,7) -> 2*
    .0(7,6) -> 2*
    10() -> 6*,2,1
    i0(7) -> 3*
    i0(6) -> 3*
    i0(1) -> 3*
    11() -> 6,7*,2,1,3
    1 -> 2*
    6 -> 2*
    7 -> 2*
  problem:
   
  Qed