R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logic-based languages. Science of Computer Programming, 30(1--2):119--155, 1998.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....achieve similar precision without additional techniques. 2 This discussion points the way to an extension of other analysis domains: for each domain of elements d we can consider the domain of elements of the form c ) d, where c is a constraint. Some work in this direction has already been done [3]. 9.1.2 Top down Execution with Memoing Our second application is to systems that employ a top down execution with memoization (or tabulation) of answers to calls to predicates. This approach has been used successfully in some logic programming and deductive database systems. XSB [35] is a prime ....

R. Bagnara, A Hierarchy of Constraint Systems for Data-Flow Analysis of Constraint LogicBased Languages, manuscript, 1995.

....sections can potentially reduce the complexity of convex hull calculations, can be implemented easily without CLP(R) support, but are likely to sacrifice a lot of precision. Moreover, the representation is likely to become intractable for predicates of larger arity. Interval Approximations China [1, 2, 3] is an analyser for CLP(R) and CLP(FD) that approximates conjunctions of constraints with bounding boxes. Bounding boxes are rectangular regions with sides parallel to the axes that are obtained by projecting variables onto their axes in order to represent each variable with the interval that ....

....parallel to the axes that are obtained by projecting variables onto their axes in order to represent each variable with the interval that results from the projection. Interval widening is required for termination and constraints are solved by propagating constraints around a constraint network [1, 2]. The bounding box approximation has been chosen for tractability, but our work suggests that, with some thought, it is not difficult to implement a more precise analysis with polyhedral approximations. To be fair, however, China [2] introduces some nice ideas like, for example, the way ....

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R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logic-based languages. Technical Report TR-96-10, Dipartimento di Informatic'a, Universita di Pisa corso Italia 40, 56125 Pisa, Italy, 1996.

....domains to exchange information each other (and with an external environment) through a particular type of functions, called queries. Due to its peculiar features, the open product differs substantially from our reduced relative power, and it is, in general, uncomparable. Bagnara has developed in [5] an elegant meta language for abstract domain manipulation based on a subset of a concurrent constraint (cc) language ( 57] where a domain is required to be a particular kind of an ask and tell constraint system. Bagnara s framework offers a way to combine such domains with asynchronous ....

R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logic-based languages. Sci. Comput. Program., 1997. To appear.

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R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logic-based languages. Science of Computer Programming, 30(1--2):119--155, 1998.

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R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logic-based languages. Science of Computer Programming, 30(1--2):119--155, 1998.

No context found.

R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logic-based languages. Science of Computer Programming, 30(1--2):119--155, 1998.

No context found.

R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logic-based languages. Science of Computer Programming, 30(1--2):119--155, 1998.

No context found.

R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logic-based languages. Science of Computer Programming, 30(1--2):119--155, 1998.

....possibility of combining domains in a novel and interesting way. Following this methodology, the asynchronous interaction between domains can be expressed with all the elegance which derives from the cc framework. For space reasons we have omitted many details. The interested reader is referred to [4], a much longer version of this paper including all the proofs and more examples. The plan of the paper is as follows: Section 2 introduces some basic notions and notations used throughout the paper. Section 3 explains our generalized semantics for CLP languages, as well as the abstract ....

....of the domain [15] The way we define domains of interpretation for CLP languages is clearly highly dependent on the application we have in mind. For our current purposes we restrict ourselves to a specific class of domains which is obtained by imposing restrictions on the general scheme (see [4]) For a full understanding of the hypotheses which are behind our approach, we now spell out the above mentioned restrictions. This makes clear what is the class of properties which are captured by the hierarchy of domains that will be presented later. We are interested properties of programs ....

R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logic-based languages. Technical Report TR-96-10, Dipartimento di Informatica, Universit`a di Pisa, 1996.

....of combining domains in a novel and interesting way. By following this methodology, the asynchronous interaction between domains can be expressed with all the elegance that derives from the cc framework. For space reasons we have omitted many details. The interested reader is referred to [4], a much longer version of this paper including all the proofs and more examples. The plan of the paper is as follows: Section 2 introduces some 2 basic notions and notations used throughout the paper. Section 3 explains our generalized semantics for CLP languages, as well as the abstract ....

....of the domain [16] The way we define domains of interpretation for CLP languages is clearly highly dependent on the application we have in mind. For our current purposes we restrict ourselves to a specific class of domains that is obtained by imposing restrictions on the general scheme (see [4]) For a full understanding of the hypotheses that are behind our approach, we now spell out the above mentioned restrictions. This makes clear what is the class of properties that are captured by the hierarchy of domains that will be presented later. We are interested in properties of ....

R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logic-based languages. Technical Report TR-96-10, Dipartimento di Informatica, Universita di Pisa, 1996.

....matter. 4 Parametric Structural Analysis In order to specify the abstract domain for the analysis, we need some assumptions on the concrete X domain D # X , which represents the X part of consistent constraint stores. One can think about D # X as made up of first order sentences [5]. In this view, the operator# : D # X D # X # D # X corresponds to logical conjunction. Moreover, we assume that it makes sense to talk about the free variables of D # # D # X , denoted by FV (D # ) Let s, t, u # T # z and D # , E # # D # X such that FV (D # ) # ....

R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logicbased languages. To appear in Science of Computer Programming. Extended version available as TR-96-10, Dipartimento di Informatica, Universita di Pisa, 1997.

....stores. Following [13] it is not at all restrictive to 7 assume that, in order to define the concrete semantics of programs, four operations over C # need to be characterized. These model the constraint accumulation process, parameter passing, projection, and renaming apart (see also [2, 3] on this subject) Constraint accumulation is modeled by the binary operator # : C # C # # C # and the unsatisfiability condition in the constraint solver is modeled by the special value # # # C # . Notice that, while # may be reasonably expected to satisfy certain properties, ....

....ensure renaming apart. Similarly, we will write (u, G # ) # # ( t, C # ) # meaning that u = #( t) and that G # has been obtained from C # by applying the same renaming applied to t in order to obtain u. It is often helpful to think of C # as made up of first order formulas [3]: in this view, # is logical conjunction, parameter passing amounts to conjunction of a formula with an equality formula, and # # corresponds to existential quantification on the variables in Vars #. While this is exactly how the intended semantics of CLP languages is captured, ....

R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logic-based languages. Science of Computer Programming, 30(1--2):119--155, 1998.

....not really matter. 4 Parametric Structural Analysis In order to specify the abstract domain for the analysis, we need some assumptions on the concrete X domain D [ X , which represents the X part of consistent constraint stores. One can think about D [ X as made up of first order sentences [5]. In this view, the operator Omega : D [ X Theta D [ X D [ X corresponds to logical conjunction. Moreover, we assume that it makes sense to talk about the free variables of D [ 2 D [ X , denoted by FV (D [ Let s; t; u 2 T z and D [ E [ 2 D [ X such that FV (D [ ....

R. Bagnara. A hierarchy of constraint systems for data-flow analysis of constraint logicbased languages. To appear in Science of Computer Programming. Extended version available as TR-96-10, Dipartimento di Informatica, Universit`a di Pisa, 1997.

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