YES(?,O(n^2))

Problem:
 f(+(x,0())) -> f(x)
 +(x,+(y,z)) -> +(+(x,y),z)

Proof:
 RT Transformation Processor:
  strict:
   f(+(x,0())) -> f(x)
   +(x,+(y,z)) -> +(+(x,y),z)
  weak:
   
  Matrix Interpretation Processor:
   dimension: 1
   interpretation:
    [f](x0) = x0 + 17,
    
    [+](x0, x1) = x0 + x1,
    
    [0] = 1
   orientation:
    f(+(x,0())) = x + 18 >= x + 17 = f(x)
    
    +(x,+(y,z)) = x + y + z >= x + y + z = +(+(x,y),z)
   problem:
    strict:
     +(x,+(y,z)) -> +(+(x,y),z)
    weak:
     f(+(x,0())) -> f(x)
   Matrix Interpretation Processor:
    dimension: 2
    interpretation:
                    [0]
     [f](x0) = x0 + [2],
     
                        [1 1]     [8 ]
     [+](x0, x1) = x0 + [0 1]x1 + [10],
     
           [0]
     [0] = [0]
    orientation:
                       [1 1]    [1 2]    [26]        [1 1]    [1 1]    [16]              
     +(x,+(y,z)) = x + [0 1]y + [0 1]z + [20] >= x + [0 1]y + [0 1]z + [20] = +(+(x,y),z)
     
                       [8 ]        [0]       
     f(+(x,0())) = x + [12] >= x + [2] = f(x)
    problem:
     strict:
      
     weak:
      +(x,+(y,z)) -> +(+(x,y),z)
      f(+(x,0())) -> f(x)
    Qed