NO

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

Proof:
 Unfolding Processor:
  loop length: 2
  terms:
   a(a(b(b(b(b(x9))))))
   b(b(b(b(b(a(a(a(a(a(b(b(x9))))))))))))
  context: b(b(b(b(b(a([]))))))
  substitution:
   x9 -> b(a(a(a(a(a(x9))))))
  Qed