J. Jaffar, J-L. Lassez, Constraint Logic Programming, Proc. Conf. on Principles of Programming Languages, 1987, 111--119.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....of a possibly infinite collection of tuples from a Cartesian product D 1 D 2 : D n , where D 1 ; D n are arbitrary domains. The idea of using the duality between constraints and sets of points they define in programming systems goes to constraint logic programming (e.g. [JaL87]) The MDS objects we study here are strongly related to, and contain as a subfamily, generalized relations in [KKR90] and CST objects using linear constraints over reals in [BK95] that we used in the motivating example) 7.1 Constraint Formulae vs. Multidimensional Sets Although MDS ....

J. Jaffar, J-L. Lassez, Constraint Logic Programming, Proc. Conf. on Principles of Programming Languages, 1987, 111--119.

....solvers are hard coded in the language C, whereas ECLiPSe s are written in itself for easier modification. Generalized constraint propagation technique are also used in ECLiPSe. One of the founding works on CLP was carried out by J. Jaffar and J.L. Lassez at Monash University in Melbourne [17]. They have presented the CLP(X) system, which was later specialized for several computation domains: CLP(R) for real linear arithmetic (at Monash University, IBM Yorktown Heights research facility, and Carnegie Mellon University) CLP(Q) for rational numbers, and CLP(Z) for integers. The ....

Jaffar, J. and Lassez, J.-L., Constraint Logic Programming, 14th ACM Symp. on Principles of Programming Languages, Munich, 1987.

....constraint based query evaluation, compilation techniques, linear recursions, functional recursions, recursive query processing, query optimization. 1. Introduction Constraint programming and constraint based reasoning has been studied extensively in logic programming and artificial intelligence [12, 13]. Since many application problems in deductive databases, such as traversal recursion [24] the manipulation of lists and complex data objects [9] etc. may involve huge search space and may encounter termination problems, it is important to explore constraint based query evaluation in deductive ....

....functions and higher order logic. Thirdly, our study has been focused on the static control of query execution, in which the flow of execution is predetermined at query compilation and analysis time, which is different from most expert systems which adopt dynamic control in query execution [13]. Although static control, exercised by a query optimizer, is suitable for finding all the answers to the query, dynamic control, exercised by the system at run time, often benefits the queries for finding one or a few good answers. To facilitate the dynamic control of query execution, our ....

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J. Jaffar and J. Lassez, Constraint Logic Programming, Proc. 14th ACM Symp. Principles of Programming Languages, Munich, Germany, 1987, 111-119.

....Prologs are rational trees. Although such implementations undermine somewhat the view of Prolog as a Horn clause theorem prover, they have been retained because there is a lower overhead in frequently used unifications. There are, in any case, logical semantics for programs in such languages (see [11, 12, 10]) which reflect closely the standard logical semantics of logic programs (as given, for example, in [14] This work extends with only minor changes to the problem of representing sets of infinite trees. Infinite trees can be viewed as a formalization of potentially infinite data structures such ....

J. Jaffar & J-L. Lassez, Constraint Logic Programming, Proc. Conf. on Principles of Programming Languages, 111--119, 1987.

....of a possibly infinite collection of tuples from a Cartesian product D 1 D 2 : D n , where D 1 ; D n are arbitrary domains. The idea of using the duality between constraints and sets of points they define in programming systems goes to constraint logic programming (e.g. [JaL87]) The MDS objects we study here are strongly related to, and contain as a subfamily, generalized relations in [KKR90] and CST objects using linear constraints over reals in [BK95] that we used in the motivating example) 11 . 7.1 Constraint Formulae vs. Multidimensional Sets Although MDS ....

J. Jaffar, J-L. Lassez, Constraint Logic Programming, Proc. Conf. on Principles of Programming Languages, 1987, 111--119.

....to predict the likely motion of targets [CT84] However, no general unified technology and the productivity tools for spatio temporal data fusion and sensor management was considered. Existing DBMS do not deal with and manipulate constraints as stored data. 3 Constraint Logic Programming [JaL87, DVS88, Prolog3] on the other hand was not designed to deal with large amounts of stored data, and support spatio temporal features. Extensions of DBMS with spatio temporal operators [OrM88, G89, W89, He90] typically (1) are limited to low (two or, at most three ) dimensional space, 2) have restrictions in ....

J. Jaffar, J-L. Lassez, Constraint Logic Programming, Proc. Conf. on Principles of Programming Languages, 1987, 111-119.

....constructing for each sub formula a finite representation of its value. This process is much more efficient than the tuple based evaluation. However, the expressive power of first order queries in this domain is severely limited. This motivated research into using constraint logic programs (see [JL87, JM94] for querying finitely representable databases over the integer order. Logic programs without negation, when they terminate, result in f.r. answers too. This means that the result of one program, or its negation, can be used as input for another program. This leads to the notion of Datalog ....

J. Jaffar and J.-L. Lassez, Constraint logic programming, Proc. 14th ACM Symp. on Principles of Programming Languages, 1987, pp. 111--119.

....filters are reviewed and the fault isolation procedure is described. Experimental results are given in section 5, together with the computed diagnoses. Finally, some concluding remarks are drawn. 2 Modeling Analog Circuits with CLP( 2. 1 The CLP( language Constraint Logic Programming (CLP, [Jaffar and Lassez, 1987, Cohen, 1990] is a generalization of logic programming. Unification, the basic operation in logic programs, is replaced by a more general mechanism of constraint satisfaction over a specific computation domain. An instance of the general CLP scheme is obtained by selecting a computation domain, ....

Jaffar, J., Lassez, J.-L. Constraint logic programming. Proc. 14th ACM Symp. on Principles of Programming Languages, pp. 111-119, Munich, 1987.

....by a logic programming system like Prolog. This also avoids incomplete constraint propagation which occurs in most ATMS based systems [6] Furthermore, without any change to the diagnostic algorithm, TP can be realized by different instances of the Constraint Logic Programming (CLP) scheme [10], depending on the domain of application. In section 2 we give a new characterization of models, diagnoses and conflicts, and show how to represent different types of models by logic programs. This is illustrated by the frequently used binary adder example; in section 4 the example is expanded and ....

....(a model) of the system s components and their connections. Most diagnostic systems represent models in terms of constraints coupled with an ATMS [6, 7] or as a set of propositions in first order logic [18] In contrast, we represent models by logic programs [11] and by constraint logic programs [10]. Similar representation was proposed in [19] but the origin goes back to the KARDIO model [1] Definitions of basic concepts typically follow [18] we give an alternative, relational characterization, suitable for model representation by (constraint) logic programs. Definition. A model of a ....

Jaffar, J., Lassez, J.-L. Constraint logic programming. Proc. 14th ACM Symp. on Principles of Programming Languages, 111--119, Munich, 1987.

....solving. This shows the practicability of the proposal. 1 Introduction Constraints play a central role in present days research, development and application of logic programming languages (see [12] for a survey) Most of the interest in this field started with the proposal of the CLP (X ) scheme [11], a general framework for constraint logic programming (CLP) languages. The CLP (X ) scheme was conceived hand by hand with one of its most prominent instances, the language CLP (R) 13] which extended traditional logic programming by the use of real arithmetic constraints for expressing ....

Jaffar J., Lassez J.L.: Constraint Logic Programming. Procs. of the 14th ACM Symp. on Principles of Programming Languages, 114--119, Munich 1987.

....solving. This shows the practicability of the proposal. 1 Introduction Constraints play a central role in present days research, development and application of logic programming languages (see [15] for a survey) Most of the interest in this eld started with the proposal of the CLP (X ) scheme [14], a general framework for constraint logic programming (CLP) languages. The CLP (X ) scheme was conceived hand by hand with one of its most prominent instances, the language CLP (R) 16, 17] which extended traditional logic programming by the use of real arithmetic constraints for expressing ....

Jaoear J., Lassez J.L.: Constraint Logic Programming. Procs. of the 14th ACM Symp. on Principles of Programming Languages, 114119, Munich 1987.

....system like Prolog. This also avoids incomplete constraint propagation which occurs in most ATMS based systems [de Kleer and Williams, 1987] Furthermore, without any change to the diagnostic algorithm, TP can be realized by different instances of the Constraint Logic Programming (CLP) scheme [Jaffar and Lassez, 1987], depending on the domain of application. In section 2 we give a new characterization of models, diagnoses and conflicts, and show how to represent different types of models by logic programs. This is illustrated by the frequently used binary adder example; in section 4 the example is expanded and ....

.... systems represent models in terms of constraints coupled with an ATMS [de Kleer and Williams, 1987, de Kleer and Williams, 1989] or as a set of propositions in first order logic [Reiter, 1987] In contrast, we represent models by logic programs [Lloyd, 1987] and by constraint logic programs [Jaffar and Lassez, 1987, Cohen, 1990] Similar representation was proposed in [Saraswat et al. 1990] but the origin goes back to the KARDIO model [Bratko et al. 1989] Definitions of basic concepts typically follow [Reiter, 1987] we give an alternative, relational characterization, suitable for model ....

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Jaffar, J., Lassez, J.-L. Constraint logic programming. Proc. 14th ACM Symp. on Principles of Programming Languages, pp. 111--119, Munich, 1987.

....constraints in the form of user definable Constraint Handling Rules (CHRs, Fr95] Example 1. 3 (CLP) Goal: X 1 1 Y Y X IC : X Y Y Z X Z X N N X false A CLP system working over a finite integer domain (such as cc(FD) VHSaDe93] or the domain of real numbers (CLP(R) [JaLa87]) does not need the explicit integrity constraints as its constraint solver recognizes that the constraints in the goal are unsatisfiable over their respective domains. Used as CHRs, the first integrity constraint (transitivity) adds X Y 1 X to the goal. The second integrity constraint then ....

Jaffar, J.; Lassez, J.-L.: Constraint Logic Programming, Proc. of the 14 th ACM Symp. on the Principles of Programming Languages, pp. 111--119, 1987

....into explanations. Thus the use of ICs in SQO and ALP is similar, with extensional, respectively intensional, predicates in SQO taking the role of abducible, respectively ordinary, predicates in ALP. This similarity was first noticed by Kakas [16, 17] Constraint Logic Programming (CLP, [13, 14]) also considers two kinds of predicates, ordinary predicates, processed by backward reasoning with clauses in a given logic program, and constraint predicates, simplified and checked for satisfiability by a built in constraint solver. A given goal is solved when it is reduced to a set of ....

....user define the constraint solver. Example 3. CLP) Goal: X 1 1 Y Y X ICs: X Y Y Z X Z X N N X false. A CLP system employing a built in constraint solver working either over a finite integer domain (such as cc(FD) 30] or over the domain of real numbers (CLP(R) [13]) does not need the explicit ICs as the constraint solver recognizes that the constraints in the goal are unsatisfiable over their respective domains. If no built in constraint solver is present, the ICs can be used as CHRs to determine the unsatisfiability of the goal: the first IC (transitivity) ....

Jaffar, J.; Lassez, J.-L.: Constraint Logic Programming, Proc. of the 14 th ACM Symp. on the Principles of Programming Languages, pp. 111--119, 1987

....This shows the practicability of the proposal. 1 Introduction Constraints play a central role in present days research, development and application of logic programming (LP) languages (see [15] for a survey) Most of the interest in this field started with the proposal of the CLP (X ) scheme [14], a general framework for constraint logic programming (CLP) languages. The CLP (X ) scheme was conceived hand by hand with one of its most prominent instances, the language CLP (R) 16] which extended traditional LP by the use of real arithmetic constraints for expressing conditions in clauses ....

Jaffar J., Lassez J.L.: Constraint Logic Programming. Procs. of the 14th ACM Symp. on Principles of Programming Languages, 114--119, Munich 1987.

....and will influence the semantics of the data model and language only in the sense that we may have constraints with different canonical form which represent the same CST object. This issue will be taken below when we consider the comparison of oids of CST objects. 3. 2 Constraint Objects As in [JaL87, KKR93, BJM93]) we view constraints as another means to represent a (possibly infinite) collection of points in (n dimensional) space. For example, a constraint such as ( x; y)j 2x 3y 5 ) can be viewed as the infinite collection of points in 2 : f(a 1 ; a 2 )j 2a 1 3a 2 5 g. In general, we say that a ....

....not well integrated with available DBMS. This causes an impedance mismatch in terms of query manipulation, and prevent efficient implementation of query evaluation over constraint databases. Existing DBMS do not deal with and manipulate constraints as stored data 2 . Constraint Logic Programming [JaL87, CHIP, Prolog3] on the other hand was not designed to deal with large amounts of stored data, and support spatio temporal features. Extensions of DBMS with spatio temporal operators [OrM88, Gut89, HaC91] are typically limited to low (two or, at most three ) dimensional space, have restrictions on using these ....

J. Jaffar, J-L. Lassez, Constraint Logic Programming, Proc. Conf. on Principles of Programming Languages, 1987, 111--119.

....theories into DATALOG [KKR90] Our work is at a lower level since we deal with the actual resolution of constraints, not their integration into another language. For instance, if we use this work as a theory of constraints over an order sorted domain, it makes perfect sense to study CLP(O) [JL87], where O is our order sorted domain. This is actually a subject for further research, such as using this constraint theory for the constraint scheme used for LIFE [AKP90] As a contribution to the theory of constraints over an order sorted domain, this approach is very general and could be ....

J. Jaffar, J.-L. Lassez. Constraint Logic Programming. Proc. ACM Symp. Principles of Programming Languages, San Francisco, 1987.

....G.1.6 [ Constrained Optimization. General Terms: Languages, Theory Additional Key Words and Phrases: constraint logic program, semantics. 1 Introduction One of the most promising innovations in recent programming language design is the amalgamation of constraint programming and logic programming [8]. Constraints provide a powerful and natural programming paradigm, in which the objects of computation are not explicitly constructed but rather they are implicitly defined using constraints. Applications for constraint logic programming languages have been in many diverse areas. They include ....

....in traditional operations research problems, such as cutting stock and scheduling. Pure constraint logic programming languages only provide for testing constraint satisfaction, however, many applications desire an optimal solution. For this reason, although the standard semantics of CLP languages [8] does not include optimization operators, some existing CLP languages provide ad hoc non logical optimization [3] and in other languages, optimization may be obtained using meta level facilities [7] We address the problem of giving a simple declarative semantics for optimization which has a ....

Jaffar, J. and Lassez, J.-L. Constraint logic programming. Proc. Fourteenth Ann. ACM Symp. Principles of Programming Languages (San Francisco, California, 1987) 111-119.

.... a one step consequence function, a least Herbrand model and numerous relationships between them: soundness and completeness of SLD refutations, soundness and completeness of the negation asfailure rule, These attributes were generalized in the constraint logic programming scheme [8, 9] to achieve similarly satisfactory semantics for logic programs with constraints over some domain. The domain was a parameter in the constraint logic programming scheme. There are very few results for logic programs which do not have corresponding results for constraint logic programs. The strong ....

....concerning constraint satisfaction. We have made no use of it in this paper, but nevertheless we give a characterization of when EFT and related theories are model complete in the belief that these results will eventually prove helpful. Solution compactness was introduced by Jaffar and Lassez [8, 9] as the requirement on a constraint domain for the CLP scheme to be applicable. We first survey and elucidate several aspects of solution compactness. Then we address the problem of characterizing those models of Clark s axioms which form solution compact constraint domains. This turns out to be a ....

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J. Jaffar & J-L. Lassez, Constraint Logic Programming, Proc. Conf. on Principles of Programming Languages, 1987, 111--119.

....apply to constraint logic programming (CLP) In viewing the theory of constraint logic programming as lifted from the theory of logic programming, we are taking a logic programming view of CLP. Several papers have dealt with this problem for specific results, mostly inspired by the CLP Scheme [10, 11]. These have been on as diverse areas as general resolution [2] computed answer semantics [6] languages for concurrency [24, 30] program transformation [28] constructive negation [33] However, often it seems necessary to reproduce known logic programming results in the CLP setting, and these ....

....for top down execution, termination for bottom up evaluation, and containment and equivalence problems for CLP programs. We also point out some other properties that prevent the direct lifting of results or methods. After some preliminary definitions, we begin by presenting the CLP Scheme [10, 11]. We reformulate some aspects, and further formalize some others. As a result, we show that one part of the solution compactness condition can be removed without affecting the results of [10, 11] and that the other part is both necessary and sufficient. We then examine the effects of the ....

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J. Jaffar & J-L. Lassez, Constraint Logic Programming, Proc. Conf. on Principles of Programming Languages, 1987, 111--119.

....must return as an answer :9v (x = nil y = v:nil z = v:nil) 9v (x = v:nil y = nil z = v:nil) Thus, again, Theorem 5 forces upon us an execution mechanism capable of handling inequalities. The general runtime method faces the same problems. Since the use of constraints has many advantages [11] and substitutions are too weak to represent the appropriate negative information, most approaches to constructive negation are based on constraints [28, 19, 43, 1, 41] rather than substitutions. The algorithm uncover is useful for reducing :s 1 : sm , and the formulas produced by the ....

J. Jaffar & J-L. Lassez, Constraint Logic Programming, Proc. Conf. on Principles of Programming Languages, 111--119, 1987.

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J. Jaffar & J-L. Lassez, Constraint Logic Programming, Proc. Conf. on Principles of Programming Languages, 1987, 111--119.

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