Evaluating software verification systems: benchmarks and competitions

This report documents the program and the outcomes of Dagstuhl Seminar 14171 “Evaluating Software Verification Systems: Benchmarks and Competitions”. The seminar brought together a large group of current and future competition organizers and participants, benchmark maintainers, as well as practitioners and researchers interested in the topic. The seminar was conducted as a highly interactive event, with a wide spectrum of contributions from participants, including talks, tutorials, posters, tool demonstrations, hands-on sessions, and a live competition

Continuation semantics for PROLOG with cut

We present a denotational continuation semantics for PROLOG with cut. First a uniform language B is studied, which captures the control flow aspects of PROLOG. The denotational semantics for B is proven equivalent to a transition system based operational semantics. The congruence proof relies on the representation of the operational semantics as a chain of approximations and on a convenient induction principle. Finally, we interpret the abstract language B such that we obtain equivalent denotational and operational models for PROLOG itself

Contextual Permission: A Solution to the Free Choice Paradox

In this paper, we give a solution to the Free Choice Paradox. This is done in two stages. First, we have a close look at the logical interpretation of the natural language statements that lead to the paradox. This leads to making the important distinction of permitting an action in isolation or permitting it in combination with some or any other action, i.e. in a certain context. This distinction is made formal by the introduction of a new operator on actions, which forces them to be performed in isolation. With this distinction made clear it is possible to give a "new", stronger definition for the permission operator, which solves the Free Choice Paradox and which does not lead to any new inconsistencies or paradoxes

Free choice and contextually permitted actions

We present a solution to the paradox of free choice permission by introducing strong and weak permission in a deontic logic of action. It is shown how counterintuitive consequences of strong permission can be avoided by limiting the contexts in which an action can be performed. This is done by introducing the only operator, which allows us to say that only is performed (and nothing else), and by introducing contextual interpretation of action term

Four domains for concurrency

AbstractWe give four domains for concurrency in a uniform way by means of domain equations. The domains are intended for modelling the four possible combinations of linear time versus branching time, and of interleaving versus noninterleaving concurrency. We use the linear time, noninterleaved domain to give operational and denotational semantics for a simple concurrent language with recursion, and prove that O = D

Four domains for concurrency

AbstractWe give four domains for concurrency in a uniform way by means of domain equations. The domains are intended for modelling the four possible combinations of linear time versus branching time, and of interleaving versus noninterleaving concurrency. We use the linear time, noninterleaved domain to give operational and denotational semantics for a simple concurrent language with recursion, and prove that O = D

Denotational semantics for unguarded recursion: the demonic case

We show that the technique to prove equivalence of operational and denotational cpo based semantics using retractions, as introduced in de Bruin & Vink [1989] for a sequential backtracking language, can be applied to parallel languages as well. We prove equivalence for a uniform language in which procedure calls need not be guarded. The unguardedness is taken care of by giving a semantics in which the nondeterminism is demonic