YES(?,O(n^2))

Problem:
 a(b(a(x1))) -> b(a(x1))
 b(b(b(x1))) -> b(a(b(x1)))
 a(a(x1)) -> b(b(b(x1)))

Proof:
 Matrix Interpretation Processor:
  dimension: 2
  interpretation:
             [1 0]     [4]
   [b](x0) = [0 0]x0 + [0],
   
             [1 1]     [1 ]
   [a](x0) = [0 1]x0 + [13]
  orientation:
                 [1 1]     [6 ]    [1 1]     [5]           
   a(b(a(x1))) = [0 0]x1 + [13] >= [0 0]x1 + [0] = b(a(x1))
   
                 [1 0]     [12]    [1 0]     [9]              
   b(b(b(x1))) = [0 0]x1 + [0 ] >= [0 0]x1 + [0] = b(a(b(x1)))
   
              [1 2]     [15]    [1 0]     [12]              
   a(a(x1)) = [0 1]x1 + [26] >= [0 0]x1 + [0 ] = b(b(b(x1)))
  problem:
   
  Qed