@TechReport{Tullsen:RR2000,
  author =       "Mark Tullsen",
  title =        "The Zip Calculus",
  institution =  "Yale University",
  month =        feb,
  year =         "2000",
  number =       "YALEU/DCS/RR-1191",
  abstract =     "Many have recognized the need for genericity in
                  programming and in program transformation.
                  Genericity over data types has been achieved with
                  polymorphism.  Genericity over type constructors,
                  often referred to as polytypism, is an area of
                  active research.  However, genericity over the
                  length of tuples has not been achieved in a typed
                  language.  This paper shows the usefulness of such
                  genericity and presents the zip calculus, an
                  extension of a typed lambda calculus that gives
                  genericity over the length of tuples.",
}