Section 10-8.1. Rule against perpetuities; time at which permissible period

begins
    (a) Where an estate is created by an instrument exercising a power  of
  appointment,  the  permissible  period  of the rule against perpetuities
  begins:
    (1) In the case of an instrument exercising a general power  which  is
  presently  exercisable,  on  the  effective  date  of  the instrument of
  exercise.
    (2) In all other cases, at the time of the creation of the power.
    (b) Where the creator of a trust reserves to  himself  an  unqualified
  power to revoke, the permissible period of the rule against perpetuities
  begins when the power to revoke terminates by reason of the death of the
  creator, by a release of such power or otherwise.