695. (a) Unless the power to revoke is in the creating instrument
or exists pursuant to Section 15400, the creation of a power of
appointment is irrevocable.
(b) Unless made expressly irrevocable by the creating instrument
or the instrument of exercise, an exercise of a power of appointment
is revocable if the power to revoke exists pursuant to Section 15400
or so long as the interest in the appointive property, whether
present or future, has not been transferred or become distributable
pursuant to the appointment.
(c) Unless the power to revoke is reserved in the instrument
releasing the power, a release of a power of appointment is