Section 9-1.1. Rule against perpetuities

(a)  (1)  The absolute power of alienation is suspended when there are
  no persons in being by whom an absolute fee or estate in possession  can
  be conveyed or transferred.
    (2) Every present or future estate shall be void in its creation which
  shall  suspend  the  absolute  power  of alienation by any limitation or
  condition for a longer period than lives in being at the creation of the
  estate and a term of not more than  twenty-one  years.  Lives  in  being
  shall  include  a  child conceived before the creation of the estate but
  born thereafter. In no case shall the lives  measuring  the  permissible
  period  be  so  designated  or so numerous as to make proof of their end
  unreasonably difficult.
    (b) No estate in property shall be valid unless it must  vest,  if  at
  all, not later than twenty-one years after one or more lives in being at
  the  creation  of the estate and any period of gestation involved. In no
  case shall lives measuring the  permissible  period  of  vesting  be  so
  designated  or  so  numerous  as to make proof of their end unreasonably
  difficult.