34,672 research outputs found
Propositional dynamic logic for searching games with errors
We investigate some finitely-valued generalizations of propositional dynamic
logic with tests. We start by introducing the (n+1)-valued Kripke models and a
corresponding language based on a modal extension of {\L}ukasiewicz many-valued
logic. We illustrate the definitions by providing a framework for an analysis
of the R\'enyi - Ulam searching game with errors.
Our main result is the axiomatization of the theory of the (n+1)-valued
Kripke models. This result is obtained through filtration of the canonical
model of the smallest (n+1)-valued propositional dynamic logic
Abstract State Machines 1988-1998: Commented ASM Bibliography
An annotated bibliography of papers which deal with or use Abstract State
Machines (ASMs), as of January 1998.Comment: Also maintained as a BibTeX file at http://www.eecs.umich.edu/gasm
Soft Concurrent Constraint Programming
Soft constraints extend classical constraints to represent multiple
consistency levels, and thus provide a way to express preferences, fuzziness,
and uncertainty. While there are many soft constraint solving formalisms, even
distributed ones, by now there seems to be no concurrent programming framework
where soft constraints can be handled. In this paper we show how the classical
concurrent constraint (cc) programming framework can work with soft
constraints, and we also propose an extension of cc languages which can use
soft constraints to prune and direct the search for a solution. We believe that
this new programming paradigm, called soft cc (scc), can be also very useful in
many web-related scenarios. In fact, the language level allows web agents to
express their interaction and negotiation protocols, and also to post their
requests in terms of preferences, and the underlying soft constraint solver can
find an agreement among the agents even if their requests are incompatible.Comment: 25 pages, 4 figures, submitted to the ACM Transactions on
Computational Logic (TOCL), zipped file
Completeness of Flat Coalgebraic Fixpoint Logics
Modal fixpoint logics traditionally play a central role in computer science,
in particular in artificial intelligence and concurrency. The mu-calculus and
its relatives are among the most expressive logics of this type. However,
popular fixpoint logics tend to trade expressivity for simplicity and
readability, and in fact often live within the single variable fragment of the
mu-calculus. The family of such flat fixpoint logics includes, e.g., LTL, CTL,
and the logic of common knowledge. Extending this notion to the generic
semantic framework of coalgebraic logic enables covering a wide range of logics
beyond the standard mu-calculus including, e.g., flat fragments of the graded
mu-calculus and the alternating-time mu-calculus (such as alternating-time
temporal logic ATL), as well as probabilistic and monotone fixpoint logics. We
give a generic proof of completeness of the Kozen-Park axiomatization for such
flat coalgebraic fixpoint logics.Comment: Short version appeared in Proc. 21st International Conference on
Concurrency Theory, CONCUR 2010, Vol. 6269 of Lecture Notes in Computer
Science, Springer, 2010, pp. 524-53
Transforming floundering into success
We show how logic programs with "delays" can be transformed to programs
without delays in a way which preserves information concerning floundering
(also known as deadlock). This allows a declarative (model-theoretic),
bottom-up or goal independent approach to be used for analysis and debugging of
properties related to floundering. We rely on some previously introduced
restrictions on delay primitives and a key observation which allows properties
such as groundness to be analysed by approximating the (ground) success set.
This paper is to appear in Theory and Practice of Logic Programming (TPLP).
Keywords: Floundering, delays, coroutining, program analysis, abstract
interpretation, program transformation, declarative debuggingComment: Number of pages: 24 Number of figures: 9 Number of tables: non
Logics for Petri nets with propagating failures
Petri nets play a central role in the formal modelling of a wide range of complex systems and scenarios. Their ability to handle with both concurrency and resource awareness justifies their spread in the current formal development practices. On the logic side, Dynamic Logics are widely accepted as the de facto formalisms to reason about computational systems. However, as usual, the application to new situations raises new challenges and issues.
The ubiquity of failures in the execution of current systems, interpreted in these models as triggered events that are not followed by the corresponding transition, entails not only the adjustment of these structures to deal with this reality, but also the introduction of new logics adequate to this emerging phenomenon.
This paper contributes to this challenge by exploring a combination of two previous works of the authors, namely the Propositional Dynamic Logic for Petri Nets [1] and a parametric construction of multi-valued dynamic logics presented in [13]. This exercise results in a new family of Dynamic Logics for Petri Nets suitable to deal with firing failures.publishe
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