YES(?,O(n^2))

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

Proof:
 Matrix Interpretation Processor:
  dimension: 2
  interpretation:
                 [1 2]     [1 2]     [4]
   [-](x0, x1) = [0 1]x0 + [0 0]x1 + [0],
   
                  [0]
   [s](x0) = x0 + [2],
   
                 [1 1]     [1 6]     [0]
   [+](x0, x1) = [0 1]x0 + [0 1]x1 + [1],
   
         [0 ]
   [0] = [12]
  orientation:
              [1 6]    [12]         
   +(0(),y) = [0 1]y + [13] >= y = y
   
               [1 1]    [1 6]    [2]    [1 1]    [1 6]    [0]            
   +(s(x),y) = [0 1]x + [0 1]y + [3] >= [0 1]x + [0 1]y + [3] = s(+(x,y))
   
              [1 2]    [28]    [0 ]      
   -(0(),y) = [0 0]y + [12] >= [12] = 0()
   
              [1 2]    [28]         
   -(x,0()) = [0 1]x + [0 ] >= x = x
   
                  [1 2]    [1 2]    [12]    [1 2]    [1 2]    [4]         
   -(s(x),s(y)) = [0 1]x + [0 0]y + [2 ] >= [0 1]x + [0 0]y + [0] = -(x,y)
  problem:
   
  Qed