YES(?,O(n^1))

Problem:
 plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z))
 plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4)))

Proof:
 Bounds Processor:
  bound: 0
  enrichment: match
  automaton:
   final states: {2}
   transitions:
    plus0(1,1) -> 2*
    s0(1) -> 1*
  problem:
   
  Qed