YES

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

Proof:
 Matrix Interpretation Processor: dim=2
  
  interpretation:
             [1 0]  
   [b](x0) = [0 0]x0,
   
             [1 1]     [0]
   [a](x0) = [1 0]x0 + [1]
  orientation:
              [2 1]     [1]    [1 1]     [0]              
   a(a(x1)) = [1 1]x1 + [1] >= [1 1]x1 + [1] = a(b(a(x1)))
   
           [1 0]      [1 0]             
   b(x1) = [0 0]x1 >= [0 0]x1 = b(b(x1))
  problem:
   strict:
    
   weak:
    b(x1) -> b(b(x1))
  Qed