YES(?,O(n^2))

Problem:
 +(0(),y) -> y
 +(s(x),0()) -> s(x)
 +(s(x),s(y)) -> s(+(s(x),+(y,0())))

Proof:
 Matrix Interpretation Processor:
  dimension: 2
  interpretation:
                  [0]
   [s](x0) = x0 + [5],
   
                      [1 1]  
   [+](x0, x1) = x0 + [0 1]x1,
   
         [4]
   [0] = [0]
  orientation:
              [1 1]    [4]         
   +(0(),y) = [0 1]y + [0] >= y = y
   
                     [4]        [0]       
   +(s(x),0()) = x + [5] >= x + [5] = s(x)
   
                      [1 1]    [5 ]        [1 1]    [4 ]                      
   +(s(x),s(y)) = x + [0 1]y + [10] >= x + [0 1]y + [10] = s(+(s(x),+(y,0())))
  problem:
   
  Qed