YES(?,O(n^3))

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

Proof:
 Matrix Interpretation Processor:
  dimension: 3
  interpretation:
             [1 0 1]     [1]
   [b](x0) = [0 0 1]x0 + [0]
             [0 0 0]     [0],
   
             [1 4 1]     [0]
   [a](x0) = [0 0 0]x0 + [0]
             [0 0 0]     [1]
  orientation:
                 [1 4 1]     [6]    [1 4 1]     [5]                       
   a(b(a(x1))) = [0 0 0]x1 + [0] >= [0 0 0]x1 + [0] = a(a(b(b(a(a(x1))))))
                 [0 0 0]     [1]    [0 0 0]     [1]                       
   
                    [1 0 5]     [4]    [1 0 5]     [3]              
   b(a(a(b(x1)))) = [0 0 0]x1 + [1] >= [0 0 0]x1 + [1] = b(a(b(x1)))
                    [0 0 0]     [0]    [0 0 0]     [0]              
  problem:
   
  Qed