YES(?,O(n^1))

Problem:
 minus(minus(x)) -> x
 minux(+(x,y)) -> +(minus(y),minus(x))
 +(minus(x),+(x,y)) -> y
 +(+(x,y),minus(y)) -> x

Proof:
 Bounds Processor:
  bound: 0
  enrichment: match
  automaton:
   final states: {4,3,2}
   transitions:
    minus0(1) -> 2*
    minux0(1) -> 3*
    +0(1,1) -> 4*
    f60() -> 1*
  problem:
   
  Qed