30,337 research outputs found
Precise Goal-Independent Abstract Interpretation of Constraint Logic Programs
AbstractWe present a goal-independent abstract interpretation framework for pure constraint logic programs, and prove the sufficiency of a set of conditions for abstract domains to ensure that the analysis will never lose precision. Along the way, we formally define pure constraint logic programming systems, give a formal semantics that is independent of the actual constraint domain, and formally define the maximally precise abstraction of a pure constraint logic program
Modular Constraint Solver Cooperation via Abstract Interpretation
Cooperation among constraint solvers is difficult because different solving
paradigms have different theoretical foundations. Recent works have shown that
abstract interpretation can provide a unifying theory for various constraint
solvers. In particular, it relies on abstract domains which capture constraint
languages as ordered structures. The key insight of this paper is viewing
cooperation schemes as abstract domains combinations. We propose a modular
framework in which solvers and cooperation schemes can be seamlessly added and
combined. This differs from existing approaches such as SMT where the
cooperation scheme is usually fixed (e.g., Nelson-Oppen). We contribute to two
new cooperation schemes: (i) interval propagators completion that allows
abstract domains to exchange bound constraints, and (ii) delayed product which
exchanges over-approximations of constraints between two abstract domains.
Moreover, the delayed product is based on delayed goal of logic programming,
and it shows that abstract domains can also capture control aspects of
constraint solving. Finally, to achieve modularity, we propose the shared
product to combine abstract domains and cooperation schemes. Our approach has
been fully implemented, and we provide various examples on the flexible job
shop scheduling problem. Under consideration for acceptance in TPLP.Comment: Paper presented at the 36th International Conference on Logic
Programming (ICLP 2020), University Of Calabria, Rende (CS), Italy, September
2020, 17 pages. v2: Fix an example in Section 3.2 (improved closure
Some considerations on the compile-time analysis of constraint logic programs
This paper discusses some issues which arise in the dataflow analysis of constraint logic programming (CLP) languages. The basic technique applied is that of abstract interpretation. First, some types of optimizations possible in a number of CLP systems (including efficient parallelization) are presented and the information that has to be obtained at compile-time in order to be able to implement such optimizations is considered. Two approaches are then proposed and discussed for obtaining this information for a CLP program: one based on an analysis of a CLP metainterpreter using standard Prolog analysis tools, and a second one based on direct analysis of the CLP program. For the second approach an abstract domain which approximates groundness (also referred to as "definiteness") information (i.e. constraint to a single valué) and the related abstraction functions are presented
Abstract Analysis of Universal Properties for tccp
[EN] The Timed Concurrent Constraint Language (tccp) is a time extension of the concurrent constraint paradigm of Saraswat. tccp was defined to model reactive systems, where infinite behaviors arise naturally. In previous works, a semantic framework and abstract diagnosis method for the language has been defined.
On the basis of that semantic framework, this paper proposes an abstract semantics that, together with a widening operator, is suitable for the definition of different analyses for tccp programs. The abstract semantics is correct and can be represented as a finite graph where each node represents a hypothetical computational step of the program containing approximated information for the variables. The widening operator allows us to guarantee the convergence of the abstract fixpoint computation.This work has been supported by the Andalusian Excellence Project P11-TIC7659.
This work has been partially supported by the EU (FEDER) and the Spanish MINECO under grant TIN 2013-45732-C4-1-P (DAMAS) and by Generalitat Valenciana PROMETEOII/2015/013Comini, M.; Gallardo Melgarejo, MDM.; Titolo, L.; Villanueva, A. (2015). Abstract Analysis of Universal Properties for tccp. Lecture Notes in Computer Science. 163-178. https://doi.org/10.1007/978-3-319-27436-2_10S163178Alpuente, M., Gallardo, M.M., Pimentel, E., Villanueva, A.: A semantic framework for the abstract model checking of tccp programs. Theor. Comput. Sci. 346(1), 58–95 (2005)Bagnara, R., Hill, P.M., Ricci, E., Zaffanella, E.: Precise widening operators for convex polyhedra. Sci Comput. Program. 58(1–2), 28–56 (2005)Comini, M., Titolo, L., Villanueva, A.: Abstract diagnosis for timed concurrent constraint programs. Theor. Pract. Log. Program. 11(4–5), 487–502 (2011)Comini, M., Titolo, L., Villanueva, A.: A condensed goal-independent bottom-up fixpoint modeling the behavior of tccp. Technical report, DSIC, Universitat Politècnica de València (2013). http://riunet.upv.es/handle/10251/34328Cousot, P., Cousot, R.: Abstract Interpretation: a unified lattice model for static analysis of programs by construction or approximation of fixpoints. In: Proceedings of the 4th ACM SIGACT-SIGPLAN Symposium on Principles of Programming Languages, Los Angeles, California, January 17–19, pp. 238–252. ACM Press, New York (1977)de Boer, F.S., Gabbrielli, M., Meo, M.C.: A timed concurrent constraint language. Inf. Comput. 161(1), 45–83 (2000)Falaschi, M. Gabbrielli, M., Marriott, K., Palamidessi, C.: Compositional analysis for concurrent constraint programming. In: Proceedings of the Eighth Annual IEEE Symposium on Logic in Computer Science, pp. 210–221. IEEE Computer Society Press, Los Alamitos (1993)Falaschi, M., Olarte, C., Palamidessi, C.: Abstract interpretation of temporal concurrent constraint programs. Theor. Pract. Log. Program. (TPLP) 15(3), 312–357 (2015)Falaschi, M., Villanueva, A.: Automatic verification of timed concurrent constraint programs. Theor. Pract. Log. Program. 6(3), 265–300 (2006)Saraswat, V.A.: Concurrent Constraint Programming. The MIT Press, Cambridge (1993)Zaffanella, E., Giacobazzi, R., Levi, G.: Abstracting synchronization in concurrent constraint programming. J. Funct. Log. Program. 6, 1997 (1997
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