Being and Change: Reasoning About Invariance

Frank S. de Boer, Stijn de Gouw

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingAcademicpeer-review


We introduce a new way of reasoning about invariance in terms of foot-prints in a Hoare logic for recursive programs with (unbounded) arrays. A foot-print of a statement is a predicate that describes that part of the state that can be changed by the statement. We define invariance of an assertion with respect to a foot-print by means of a logical operation. This new Hoare logic is applied in a new simpler and modular proof of correctness of the well-known Quicksort sorting algorithm.
Original languageEnglish
Title of host publicationCorrect System Design
Subtitle of host publicationSymposium in Honor of Ernst-Rüdiger Olderog on the Occasion of His 60th Birthday, Oldenburg, Germany, September 8-9, 2015, Proceedings
EditorsRoland Meyer , André Platzer , Heike Wehrheim
Place of PublicationCham
Number of pages14
ISBN (Electronic)978-3-319-23506-6
ISBN (Print)978-3-319-23505-9
Publication statusPublished - 2015
Externally publishedYes

Publication series

SeriesLecture Notes in Computer Science


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