@Unpublished{ABA:96:Pippenger,
  author =       "Amir M. Ben-Amram",
  year =         "1996",
  title =        "Notes on Pippenger's Comparison of Pure and Impure
                 {LISP}",
  month =        jun,
  keywords =     "LISP, pure LISP, mutation, destructive update,
                 selective update",
  summary =      "This notes arose from a talk, in which I discussed
                 Pippenger's recent result on Pure versus Impure LISP
                 (paper in POPL '96). They include an explanation of the
                 nature and significance of Pippenger's results, a
                 discussion of the limitations of the result and ensuing
                 open problems, and finally of certain follow-ups.",
  puf =          "Working paper",
}