@InProceedings{Tullsen:MPC2000,
  author =       "Mark Tullsen",
  month =        jul,
  year =         "2000",
  title =        "The Zip Calculus",
  booktitle =	 "Mathematics of Program Construction, 
                  5th International Conference, MPC 2000",
  editor =	 "Roland Backhouse and Jose Nuno Oliveira",
  publisher =	 "Springer-Verlag",
  series =	 "Lecture Notes in Computer Science",
  volume =	 "1837",
  pages =	 "28-44",
  abstract =     "Many have recognized the need for genericity in
                  programming and program transformation.  Genericity
                  over data types has been achieved with
                  polymorphism. Genericity over type constructors,
                  often called polytypism, is an area of active
                  research. This paper proposes that another kind of
                  genericity is needed: genericity over the length of
                  tuples. Untyped languages allow for such genericity
                  but typed languages do not (except for languages
                  allowing dependent types). The contribution of this
                  paper is to present the ``zip calculus,'' a typed
                  lambda calculus that provides genericity over the
                  length of tuples and yet does not require the full
                  generality of dependent types.",
}