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

Proof:
 AT confluence processor
  Complete TRS T' of input TRS:
  -(+(x,y)) -> +(-(x),-(y))
  +(x,y) -> +(y,x)
  
   T' = (P union S) with
  
   TRS P:+(x,y) -> +(y,x)
  
   TRS S:-(+(x,y)) -> +(-(x),-(y))
  
  S is linear and P is reversible.
  
   CP(S,S) = 
  
   CP(S,P union P^-1) = 
  
   CP(P union P^-1,S) = 
  -(+(y,x)) = +(-(x),-(y))
  
  
  We have to check termination of S:
  
  Matrix Interpretation Processor: dim=1
   
   interpretation:
    [-](x0) = 4x0,
    
    [+](x0, x1) = 2x0 + x1 + 4
   orientation:
    -(+(x,y)) = 8x + 4y + 16 >= 8x + 4y + 4 = +(-(x),-(y))
   problem:
    
   Qed