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Verification of Parameterized Systems Using Logic Program Transformations
, 1999
"... We show how the problem of verifying parameterized systems can be... ..."
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Cited by 20 (7 self)
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We show how the problem of verifying parameterized systems can be...
A Transformation System for Lazy Functional Logic Programs
, 1999
"... Needed narrowing is a complete operational principle for modern declarative languages which integrate the best features of (lazy) functional and logic programming. We define a transformation methodology for functional logic programs based on needed narrowing. We provide (strong) correctness results ..."
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Cited by 19 (13 self)
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Needed narrowing is a complete operational principle for modern declarative languages which integrate the best features of (lazy) functional and logic programming. We define a transformation methodology for functional logic programs based on needed narrowing. We provide (strong) correctness results for the transformation system w.r.t. the set of computed values and answer substitutions and show that the prominent properties of needed narrowing  namely, the optimality w.r.t. the length of derivations and the number of computed solutions  carry over to the transformation process and the transformed programs. We illustrate the power of the system by taking on in our setting two wellknown transformation strategies (composition and tupling). We also provide an implementation of the transformation system which, by means of some experimental results, highlights the benefits of our approach.
Transformation Rules for Locally Stratified Constraint Logic Programs
, 2004
"... We propose a set of transformation rules for constraint logic programs with negation. We assume that every program is locally strati ed and, thus, it has a unique perfect model. We give sucient conditions which ensure that the proposed set of transformation rules preserves the perfect model of ..."
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Cited by 14 (13 self)
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We propose a set of transformation rules for constraint logic programs with negation. We assume that every program is locally strati ed and, thus, it has a unique perfect model. We give sucient conditions which ensure that the proposed set of transformation rules preserves the perfect model of the programs. Our rules extend in some respects the rules for logic programs and constraint logic programs already considered in the literature and, in particular, they include a rule for unfolding a clause with respect to a negative literal.
Beyond TamakiSato Style Unfold/Fold Transformations for Normal Logic Programs
 IN ASIAN, LNCS 1742
, 1999
"... Unfold/fold transformation systems for logic programs have been extensively investigated. Existing unfold/fold transformation systems for normal logic programs allow only TamakiSato style folding using clauses from a previous program in the transformation sequence: i.e., they fold using a singl ..."
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Cited by 11 (3 self)
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Unfold/fold transformation systems for logic programs have been extensively investigated. Existing unfold/fold transformation systems for normal logic programs allow only TamakiSato style folding using clauses from a previous program in the transformation sequence: i.e., they fold using a single, nonrecursive clause. In this paper we present a transformation system that permits folding in the presence of recursion, disjunction, as well as negation. We show that the transformations are correct with respect to various semantics of negation including the wellfounded model and stable model semantics.
Automated Inductive Verification of Parameterized Protocols
 In CAV 2001
, 2001
"... A parameterized concurrent system represents an infinite family (of finite state systems) parameterized by a recursively... ..."
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Cited by 9 (1 self)
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A parameterized concurrent system represents an infinite family (of finite state systems) parameterized by a recursively...
R.: A coinduction rule for entailment of recursively defined properties
 In Stuckey, P.J., ed.: 14th CP. Volume 5202 of LNCS
, 2008
"... Abstract. Recursively defined properties are ubiquitous. We present a proof method for establishing entailment G  = H of such properties G and H over a set of common variables. The main contribution is a particular proof rule based intuitively upon the concept of coinduction. This rule allows the i ..."
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Cited by 8 (7 self)
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Abstract. Recursively defined properties are ubiquitous. We present a proof method for establishing entailment G  = H of such properties G and H over a set of common variables. The main contribution is a particular proof rule based intuitively upon the concept of coinduction. This rule allows the inductive step of assuming that an entailment holds during the proof the entailment. In general, the proof method is based on an unfolding (and no folding) algorithm that reduces recursive definitions to a point where only constraint solving is necessary. The constraintbased proof obligation is then discharged with available solvers. The algorithm executes the proof by a searchbased method which automatically discovers the opportunity of applying induction instead of the user having to specify some induction schema, and which does not require any base case. 1
Proofs by program transformations
 proceedings of Logicbased Program Synthesis and Transformation (LOPSTR
, 1999
"... ..."
Program Transformations for Automated Verification of Parameterized Concurrent Systems
, 1999
"... We show how the problem of verifying parameterized systems can be reduced to the problem of determining the equivalence of goals in a logic program. We further show how goal equivalences can be established using inductionbased proofs. Such proofs rely on a powerful new theory of logic program trans ..."
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Cited by 2 (0 self)
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We show how the problem of verifying parameterized systems can be reduced to the problem of determining the equivalence of goals in a logic program. We further show how goal equivalences can be established using inductionbased proofs. Such proofs rely on a powerful new theory of logic program transformations (encompassing unfold, fold and goal replacement transformations). We present this theory of logic program transformations which in particular, allows a more general folding rule (as compared to the state of the art). We show how our more general transformations are useful for constructing verification proofs of parameterized systems. Moreover these verification proofs can be largely automated, and are applicable to a variety of network topologies, including uni and bidirectional chains, rings, and trees of processes. Unfold transformations in our system correspond to algorithmic modelchecking steps, fold and goal replacement correspond to deductve steps. All three types of transfo...
An UnfoldingBased Semantics for Logic Programming with Aggregates
, 2006
"... The paper presents two equivalent definitions of answer sets for logic programs with aggregates. These definitions build on the notion of unfolding of aggregates, and they are aimed at creating methodologies to translate logic programs with aggregates to normal logic programs or positive programs, w ..."
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Cited by 1 (1 self)
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The paper presents two equivalent definitions of answer sets for logic programs with aggregates. These definitions build on the notion of unfolding of aggregates, and they are aimed at creating methodologies to translate logic programs with aggregates to normal logic programs or positive programs, whose answer set semantics can be used to defined the semantics of the original programs. The first definition provides an alternative view of the semantics for logic programming with aggregates described in [32,34]. In particular, the unfolding employed by the first definition in this paper coincides with the translation of programs with aggregates into normal logic programs described in [33]. This indicates that the approach proposed in this paper captures the same meaning as the semantics discussed in [32,34]. The second definition is similar to the traditional answer set definition for normal logic programs, in that, given a logic program with aggregates and an interpretation, the unfolding process produces a positive program. The paper shows how this definition can be extended to consider aggregates in the head of the rules.
On Logic Programming with Aggregates
"... In this paper, we present a translational semantics for normal logic programs with aggregates. We propose two different translations of logic programs with aggregates into normal logic programs, whose answer set semantics is used to defined the semantics of the original programs. Differently from ma ..."
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In this paper, we present a translational semantics for normal logic programs with aggregates. We propose two different translations of logic programs with aggregates into normal logic programs, whose answer set semantics is used to defined the semantics of the original programs. Differently from many of the earlier proposals in this area, our semantics does not impose any syntactic restrictions on the aggregates and the programs. The semantics naturally extends the traditional answer set semantics for normal logic programs, and it subsumes many of the previous proposals in this area, yet it overcomes several drawbacks of those proposals, e.g., by disallowing nonminimal answer sets. We also discuss how the proposed approach can be extended to logic programs with aggregates in the head, a class of programs that has rarely been considered. The new semantics is natural and intuitive, and it can be directly implemented using available answer set solvers. We describe a system, called ASP A, that is capable of computing answer sets of programs with arbitrary (possibly recursively defined) aggregates. We also present a preliminary comparison of ASP A with another system for computing answer sets of programs with aggregates, DLV A. 1