In the field of quality assurance of hybrid systems, Platzer's differential dynamic logic (dL) is widely recognized as a deductive verification method with solid mathematical foundations and sophisticated tool support. Motivated by case studies provided by our industry partner, we study a relational extension of dL, aiming to formally prove statements such as "an earlier engagement of the emergency brake yields a smaller collision speed."  A main technical challenge is to combine two dynamics, so that the powerful inference rules of dL (such as the differential invariant rules) can be applied to such relational reasoning, yet in such a way that we relate two different time points. Our contributions are a semantical theory of time stretching, and the resulting synchronization rule that  expresses time stretching by the syntactic operation of Lie derivative. We implemented this rule as an extension of KeYmaera X, by which we successfully verified relational properties of a few models taken from the automotive domain.

Relational Differential Dynamic Logic

ETAPS is a confederation of several conferences, each with its own Programme Committee and Steering Committee. ETAPS is the most important and visible annual European event related to software sciences. Altogether, more than 500 researchers participate in this event every year. The confederated conferences cover various aspects of software systems, ranging from theoretical foundations to programming language developments, compiler advancements, analysis tools, formal approaches to software engineering, and security.

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Password: Luxembourg2021

This can be used to meet in the coffee breaks.

 PDF's of the papers are available on https://etaps.org/2021/programme