Invariant

The invariants of key algorithms (new paper)

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  I have mentioned this paper before but as a draft. It has now been accepted by ACM’s Computing Surveys and is scheduled to appear in September 2014; the current text, revised from the previous version, is available [1]. Here is the abstract: Software verification has emerged as a key concern for ensuring the continued … Read more




Loop invariants: the musical

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  Actually it is not a musical but an extensive survey. I have long been fascinated by the notion of loop invariant, which describes the essence of a loop. Considering a loop without its invariant is like conducting an orchestra without a score. In this submitted survey paper written with Sergey Velder and Carlo Furia … Read more




Webinar today: the Varieties of Loop Invariants

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I did not have time to complete my Monday post this week; it will be for next Monday (title: Never design a language). In the meantime, here is the announcement for today’s Saint Petersburg Software Engineering seminar , which can be followed live at http://sel.ifmo.ru/seminar/live (19:30 Saint Petersburg time, meaning 16:30 Zurich/Paris, 7:30 PDT on … Read more




Contracts written by people, contracts written by machines

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What kind of contract do you write? Could these contracts, or some of them, be produced automatically? The idea of inferring contracts from programs is intriguing; it also raises serious epistemological issues. In fact, one may question whether it makes any sense at all. I will leave the question of principle to another post, in … Read more