Section 642 Of Article 3. Donee’s Required Intent From California Probate Code >> Division 2. >> Part 14. >> Chapter 4. >> Article 3.

. If a power of appointment existing at the donee's death, but created after the execution of the donee's will, is exercised by the will, the appointment is effective except in either of the following cases:
  (a) The creating instrument manifests an intent that the power may not be exercised by a will previously executed.
  (b) The will manifests an intent not to exercise a power subsequently acquired.