Siek, JeremyTaha, Walid2017-08-022017-08-022006-04-07Siek, Jeremy and Taha, Walid. "Gradual Typing: Isabelle/Isar Formalization." (2006) https://hdl.handle.net/1911/96348.https://hdl.handle.net/1911/96348This report formalizes a gradual type system using the Isabelle/Isar proof language and proof assistant. Gradual typing combines static typing and dynamic typing in the same language, allowing a programmer to gradual migrate portions of a program between the two typing disciplines.28 ppengYou are granted permission for the noncommercial reproduction, distribution, display, and performance of this technical report in any format, but this permission is only for a period of forty-five (45) days from the most recent time that you verified that this technical report is still available from the Computer Science Department of Rice University under terms that include this permission. All other rights are reserved by the author(s).Technical reportTR06-874