YES
Input TRS:
      1: a(a(x1)) -> b(b(b(x1)))
      2: b(b(b(b(b(x1))))) -> a(a(a(x1)))
Number of strict rules: 2
Direct POLO(bPol) ... removes: 1 2
      a 	w: x1 + 8
      b 	w: x1 + 5
Number of strict rules: 0