K. Sagonas, T. Swift, and D. Warren. Xsb as an efficient deductive database engine. In Proceedings of the 1994.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....A program Pi is said to be consistent if it has an answer set. Otherwise, it is inconsistent. Many robust and efficient systems that can compute answer sets of propositional logic programs have been developed. Two of the frequently used systems are dlv [10] and smodels [35] Recently, XSB [40], a system developed for computing the well founded model of logic programs, has been extended to compute stable models of logic programs as well. 2.2.2 Problem solving using LPASS Prolog and other early logic programming systems were geared towards answering yes no queries with respect to a ....

K. Sagonas, T. Swift, and D.S. Warren. Xsb as an efficient deductive database engine. In Proceedings of the SIGMOD, pages 442 -- 453, 1994. 53

....operators fully depends on the linearity of derivations. This has been evidenced by the fact that XSB, the best known state of the art tabling system that implements SLG resolution, disallows clauses like p( t( because the tabled predicate t occurs in the scope of a cut [23, 24, 25]. One interesting question then arises: Can we have a linear tabling method for top down evaluation of the well founded semantics of general logic programs, which resolves infinite loops and redundant computations (like SLG resolution) without sacrificing the linearity of SLDNF resolution (like ....

....computations considerably undermines its beauties. The general goal of our research is then to extend Prolog with tabling to compute the well founded semantics while resolving infinite loops and redundant computations. SLT resolution serves as a nice model for such an extension. Note that XSB [23, 25] is the only existing system that top down computes the well founded semantics of general logic programs, but it is not an extension of Prolog since SLG resolution and SLDNF resolution are quite heterogeneous. For positive programs, we have developed special methods for the implementation of ....

K. Sagonas, T. Swift and D. S. Warren, XSB as an efficient deductive database engine, in: Proc. of the ACM SIGMOD Conference on Management of Data, Minneapolis, 1994, pp. 442-453.

....based on e answer sets. In section 6 we consider consistent query evaluation. In section we consider possible extensions of the specification formalism and alternatives. In section 8 we briefly summarize related work. We conclude by outlining further work in section 9. We implemented in XSB [28], EAnswers, our own evaluator for disjunctive ex tended logic programs with exceptions. 2 Consistent Query Answers We assume a fixed set, IC, of integrity constraints associated with a fixed relational database schema. We also have a fixed, possibly infinite, database domain D. A database ....

K. Sagohas, T. Swift, and D.S. Warren. XSB as an Efficient Deductive Database Engine. In Proc. ACM SIGMOD, 1994.

....ontology based processing, e.g. by reading the exported files into a classifier such as FaCT [12] or Racer [10] In tandem with RuleML LP, we also focus on the (positive) Horn subset of FOL, which is closely related to the positive Horn subset of LP. Logic programming systems such as XSB [16], however, can access databases directly through built in predicates. Furthermore, restricted variants of logic programs, such as the ones established in this paper, can be directly implemented on top of SQL99 compliant relational databases. Hence, an LP based implementation of an ontology ....

K. Sagonas, T. Swift, and D. S. Warren. Xsb as an efficient deductive database engine. In R. T. Snodgrass and M. Winslett, editors, Proc. of the 1994.

....(performance) We believe that users of SHOE systems should be able to specify their preferences with regard to this scale. Thus, many differentknowledge base systems could be used for SHOE, with the appropriate tradeoffs in mind. At the completeness end of the scale sit systems such as XSB [31], a logic programming and deductive database system. XSB is more expressive than datalog and can thus be used as a complete reasoner for SHOE. At the performance end of the scale sit relational database management systems (RDBMS) which have been traditionally used for querying enormous quantities ....

K. Sagonas, T. Swift, and D. S. Warren, XSB as an Efficient Deductive Database Engine, in: R. T. Snodgrass and M. Winslett, editors, Proc. of the 1994.

.... transformations can be justified or discarded on the basis of a careful analysis of the intrinsic complexity of consistent query answering [15] If the original program can be transformed into a normal program, then also other efficient implementations could be used for query evaluation, e.g. XSB [30], that has been already successfully applied in the context of consistent query answering via query transformation, with non existentially quantified conjunctive queries [14] 6.2 Related work In [24] a general methodology based on disjunctive logic programs with stable model semantics is used ....

Sagonas, K.F.; Swift, T. and Warren, D.S. XSB as an Efficient Deductive Database Engine. In Proc. of the

....based on e answer sets. In section 6 we consider consistent query evaluation. In section 7 we consider possible extensions of the specification formalism and alternatives. In section 8 we briefly summarize related work. We conclude by outlining further work in section 9. We implemented in XSB [28], EAnswers, our own evaluator for disjunctive extended logic programs with exceptions. 2 Consistent Query Answers We assume a fixed set, IC, of integrity constraints associated with a fixed relational database schema. We also have a fixed, possibly infinite, database domain D. A database ....

K. Sagonas, T. Swift, and D.S. Warren. XSB as an Efficient Deductive Database Engine. In Proc. ACM SIGMOD, 1994.

....Consistent Answers , which, given a first order query Q, generates again a new query QUECA(Q) whose answers in r are consistent with IC, but as opposed to T , it guarantees termination, soundness and completeness for a larger set of integrity constraints. The implementation is done in XSB [6], a powerful logic programming system, which is provided with useful functionalities for the right implementation and operation of the consistent query answering algorithm. In Section 2, we will show the most relevant characteristics of the operator T and what makes it difficult to implement. We ....

K. F. Sagonas, T. Swift, and D. S. Warren. XSB as an Efficient Deductive Database Engine. In Proceedings of SIGMOD 1994 Conference, pages 442--453. ACM Press, 1994.

....Consistent Answers , which, given a first order query Q, generates again a new query QUECA(Q) whose answers in r are consistent with IC, but as opposed to T , it guarantees termination, soundness and completeness for a larger set of integrity constraints. The implementation is done in XSB [7], a powerful logic programming system, which is provided with useful functionalities for the right implementation and operation of the consistent query answering algorithm. In section 2, we will show the most relevant characteristics of the operator T and what makes it difficult to implement. We ....

K. F. Sagonas, T. Swift, and D. S. Warren. XSB as an Efficient Deductive Database Engine. In Proceedings of SIGMOD 1994 Conference, pages 442--453. ACM Press, 1994.

....Answers [9] This algorithm, given a first order query Q, again generates a new query QUECA(Q) whose answers in r are consistent with IC, but as opposed to T , it guarantees termination, soundness and completeness for a larger set of integrity constraints. The implementation is done in XSB [21], a powerful logic programming system, which is provided with useful functionalities for the right implementation and operation of the consistent query answering algorithm. A number of possible applications motivate the development of such an implementation. These include: Data warehousing (Data ....

....whose answers correspond to the consistent information stored in a database, we need a common framework for data, rules, queries and integrity constraints to be able to perform operations on them and elaborate the mentioned queries. Logic programming languages provide this framework and XSB [21] seems an adequate candidate. Generally speaking we prefer a LP language because the algorithms described in this article need the ability to perform unifications, substitutions and detecting subsumption. Some of the main characteristics that make XSB suitable for this application are: Tabling. ....

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K. F. Sagonas, T. Swift, and D. S. Warren. XSB as an Efficient Deductive Database Engine. In Proceedings of SIGMOD 1994.

....it easy for the student to modify existing rules or to add new rules to the rule base. This feature is essential to enable the adaptation of the translation component so that it can be tuned to the user s linguistic preferences. We have implemented PTA by using the deductive database system XSB [3]. XSB supplies a powerful framework for the development of PTA. In particular, XSB enables pure declarative logic programs in contrast to the restrictions of the SLD evaluation strategy of Prolog. Since XSB was especially developed for dataoriented applications, one of its main aims is the ability ....

....base. rule(2, 1, findword(encerrar) objhead(aventura) replsense(1, beenden) rule(3, 1, findword( prev(verb) next(verb) replword(1, und) copyfeat(2, 3) rule(3, 2, findword(de) next(unknown) prev(noun) prev(adjective, optional) prev(article) genitive(2) neworder(5, [2, 4, 3]) rule(7, 1, find(verb) detverb(1) rule(7, 2, find(noun) detnoun(1) copynoun(1) rule(7, 3, find(adjective) detadj(1) Fig. 4. Example of translation rules We believe that our personal translation assistant PTA represents a first step towards the important goal of ....

Sagonas, K., Swift, T., Warren, D. S.: XSB as an Efficient Deductive Database Engine. In: Proc. of the ACM SIGMOD International Conference on Management of Data (1994) 442--453

....arose in the deductive database approach which integrates the logic programming and relational database techniques and provides more powerful query language to support inference of large amounts of data. However, most deductive database systems such as Nail [26] LOLA [12] Glue Nail [10] XSB [33], Aditi [37] LogicBase [13] and Declare SDS [16] only support flat relations which are found inappropriate for advanced applications. A few deductive database systems that support data with complex structures such as LDL [8] and CORAL [30] are only implemented as memory based systems and do not ....

K. Sagonas, T. Swift, and D. Warren. XSB as an Efficient Deductive Database Engine. In Proceedings of the ACM SIGMOD International Conference on Management of Data, pages 442--453, Minneapolis, Minnesota, 1994.

....of the individual tasks in a repetitive session according to his personal preferences. Furthermore, we also support the automatic adjustment of the composition of a session according to the past scores for the different tasks. We have implemented CALLE by using the deductive database system XSB [8]. XSB supplies a powerful framework because it was especially developed for data oriented applications and enables pure declarative logic programming, which is essential for the scalability in large language learning applications. 3. Conclusion In this paper we have presented the CALLE system, ....

K. Sagonas, T. Swift, and D. S. Warren, XSB as an Efficient Deductive Database Engine. In: Proc. of the ACM SIGMOD Intl. Conf. on Management of Data, 1994.

....the evolution on execution models for logic programs has been achieving over the last decennium. The introduction of delays, of various types of constraint solvers, in particular the open box constraint solvers which provide an entire spectrum of different solvers combined in one, of tabulation ([26,21]) of model generation ( 14] of abductive ( 10] and inductive solvers ( 15] already provide a rich problem solving toolkit to support the knowledge engineering approach. However, as far as we know, current systems do not integrate a significant number of the above solvers into one powerful ....

Konstantinos Sagonas, Terrance Swift, and David S. Warren. XSB as an efficient deductive database engine. In Proceedings of the ACM SIGMOD International Conference on the Management of Data, pages 442--453, Minneapolis, Minnesota, May 1994. ACM Press.

....The idea is to monitor the execution and to try to prune infinitely failing branches. However, methods have to choose between pruning too much (causing incompleteness of the proof procedure) and preserving completeness but missing some infinite branches. Proof procedures with tabling such as XSB [25] are perhaps a better alternative to a completeness preserving procedure equipped with loop checking. They avoid the overhead of monitoring the execution while using a different proof procedure which, compared to SLD, reduces the number of infinite branches. In particular, they always terminate ....

....program specialisation [22, 14] the query fails if the program for the given query can be specialised into the empty program) In section 6, the different approaches are compared. Finally, in section 7, we draw some conclusions. We assume some familiarity with the basics of tabulation, e.g. [31, 25, 33]. Some of the authors of the current paper participated in a preliminary investigation of the topic [15] The current paper is an extension of the work described in [9] 2 Preliminaries A pre interpretation J of a program P consists of a domain D = fd 1 ; dm g and, for every functor f=n ....

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K. Sagonas, T. Swift, and D.S. Warren. XSB as an efficient deductive database engine. In Proceedings of SIGMOD 1994 Conf. ACM. Acm Press, 1994.

....uses a set of predefined priority values for the attributes. 2 Enhanced SDP Server Initialization Module Parser Module XSB Module Loader KB Reasoning Engine Parser Simple Service Matcher LIBWWW Module Fig. 1. Components of enhanced Bluetooth SDP B. XSB based Reasoning Engine XSB [16] is a research oriented Logic Programming system for Unix and Windows based systems. Its predecessors were PSB Prolog and SB Prolog. In using XSB as the reasoning engine for our work, we have taken advantage of a powerful indexing technique for asserted code called unification factoring that can ....

....that can improve program speed and indexing for compiled code. Large amounts of factual data imply that the data must be loaded into the knowledge base before the program can use it. The designers of XSB claim that the method of asserting clauses in XSB is the fastest method of all Prolog systems [16]. The key to the correct functioning of our reasoning engine is a knowledge base with sufficient and complete information about service instances. XSB has also been designed to interface easily with the C language. It also provides an interface to the libwww [15] package that is used to parse RDF ....

K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. In Proc. SIGMOD. ACM, 1994.

....updates by means of abduction; constraints, strong negation and abduction. The reference architecture [55] combines KS Agents (by Kowalski and Sadri [96] dynamic logic programming paradigm for updates (cf. Section 7. 5) tabling and abduction, and it is built upon the XSB Prolog system [129, 133]. INFSYS RR 1843 00 05 11 A framework for communicating agents has been suggested, in which agents have the ability of dynamically updating their knowledge base and their goals as a result of interactions with other agents, based on forward and backward reasoning. Knowledge management and ....

K. Sagonas, T. Swift, and D. Warren. XSB as an Efficient Deductive Database Engine. In R. Snodgrass and M. Winslett, editors, Proceedings of the 1994 ACM SIGMOD International Conference on Management of Data, pages 442--453. ACM Press, May 1994.

....paper we are concerned with this latter approach, the consistency method. 1 There is an interesting exception: the addition of previously computed results as redundant clauses. These can replace multistep deduction by a direct look up. This technique is known as memoization [16] or tabling [26, 6, 24, 7]. In the consistency method, computation consists of constraint propagation, which considers in turn each of the constraints and removes values that are inconsistent with the constraint. Propagation halts when none of the sets changes. In this stable state, the remaining sets sometimes identify ....

K. Sagonas, T. Swift, and D.S. Warren. XSB as an efficient deductive database engine. In Proc. of SIGMOD 1994 Conference. ACM, 1994. 11

.... der berechneten Fakten und des Terminierungsverhaltens der Magic sets Auswertung gleicht [Bry90] Der Unterschied besteht in der Implementierungstechnik: Die Verwendung einer modifizierten WAM erweist sich gegenuber heutiger Bottom up Technologie [RSS92] als um eine Groenordnung schneller [SSW94]. Der Grund liegt wohl im hoheren Reifegrad der tupelorientierten Implementierung gegenuber der mengenorientierten. Vor diesem Hintergrund schlagen wir die Sprache Sisyphos 1 vor, die in der Denkweise des Programmierers beide Auswertungsrichtungen frei kombiniert und damit die oben fur beide ....

K. Sagonas, T. Swift, and D.S. Warren. XSB as an efficient deductive database engine. In Proceedings of SIGMOD. 1994.

....and performance. This program transformation proceeds in two stages: magic sets rewriting (MSR) and bottom up to top down rewriting (BUTDR) BUTDR is a new technique, application of MSR to Prolog is also new. The transformation accepts essentially the same kind of programs as the XSB system [SSW94]. Tabled predicates must have precise modes: an argument indicated as b in the mode declaration must always be called with a fully instantiated term, a f argument with a free variable. Cut usage within tabled predicates is restricted, tabled predicates can use only stratified negation. 2 ....

K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. In Proceedings of SIGMOD. 1994.

....the insertion of missing words or the correction of a wrong word order. Finally, the result of the exercise is displayed to the user by means of the generation module for the source language. We have implemented our generic language learning environment by using the deductive database system XSB [17]. 3. Machine Translation We explain the details of the machine translation process by making use of the example in Fig. 2. The user input is first analyzed by accessing the source lexicon. We perform the tokenization of the input with the use of a flexible segmentation algorithm, which can also ....

SAGONAS, K., SWIFT, T., and WARREN, D. S., XSB as an Efficient Deductive Database Engine, in: Proc. of the ACM SIGMOD International Conference on Management of Data 1994.

....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 example. In these systems calls are placed in a table with their successful answers, and subsequent calls which are instances of tabled calls are executed by table look up. Similar techniques can be applied to CLP programs. An initial attempt is [17] Clearly memoization is pointless ....

K. Sagonas, T. Swift & D.S. Warren, XSB as an Efficient Deductive Database Engine, SIGMOD Record, 1994.

....e.g. by integrating intensional updates [5] Another important issue is the identification of tractable program classes like the class of guarded programs, for which the overhead of update evaluation is small. Statelog may be implemented on top of existing deductive systems like XSB Prolog [18] or Coral [17] Alternatively, the techniques from the database programming language Heraclitus[Alg,C] 11] which supports deltas as first class citizens, multiple virtual states, active rules and a wide variety of semantics, may be useful for an efficient implementation of state transitions. ....

K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. In Proc. ACM SIGMOD Intl. Conference on Management of Data, 1994.

....extensions (like invented values or choice, see e.g. 34] and states. These extensions are a powerful programming tool and have a similar impact on expressiveness like assuming an ordered database. A prototypical implementation of Statelog using XSB Prolog as a deductive database engine [26] has been completed recently and shows that programming in Statelog is feasible and intuitive [20] The related approach of XY stratified Datalog has been incorporated into LDL [34] Due to simplicity of the language, integration of the Statelog approach into other deductive database systems ....

K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. In Proc. ACM SIGMOD Intl. Conference on Management of Data, 1994.

.... well founded semantics [1, 10, 7, 28] In particular, SLG resolution [7] not only has various desirable theoretical properties, including goal orientedness, polynomial time data complexity, answer sharing and preservation of all three valued stable models, but also has been implemented efficiently [6, 25, 27], delivering excellent performance for query evaluation. This section discusses informally how to extend SLG resolution [7] with constructive negation. For simplicity, we consider query evaluation for only function free programs. 4.1. Tabled Evaluation with Constraints Given a function free ....

K. Sagonas, T. Swift, and D.S. Warren. XSB as an efficient deductive database engine. In ACM SIGMOD Conference on Management of Data, pages 442--453, 1994. 29

....Stony Brook, NY 11794 4400 Abstract The incorporation of tabulation into resolution methods ( 3, 5] has proven effective for computing the well founded semantics in a goal oriented manner. It has also given rise to an extremely efficient evaluation method for in memory deductive databases [12]. Perhaps because these results are quite recent, the problem of optimizing tabled clause resolution has remained open, despite the fact that optimizing term indexing has been extensively studied in Functional Programming, and optimizing program clause unification in Logic Programming. We ....

....to deductive databases, SLG evaluates programs according to the well founded model [16] terminates for programs with bounded term size, and has polynomial data complexity for Datalog programs with negation. SLG is amenable to efficient implementation, as shown by the performance of the XSB system [12]. In particular, the XSB system has been shown to compute in memory deductive database queries about an order of magnitude faster than current semi naive methods, and to compute Prolog queries with little loss of efficiency when compared to well known Prolog systems [14] Like other tabling ....

K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. In ACM SIGMOD International Conference on the Management of Data, 1994.

....of the SLG 8 meta interpreter shows that two major factors of overhead are meta interpretation and the lack of destructive assignment for managing tables of subgoals and their answers and X rules. Performance can be improved drastically either by compilation into WAMlike instructions as in Prolog [17] or through source program transformation with external table management in C using a Prolog C interface [16] Both approaches should be further explored for query evaluation of general logic programs. 34 6 Conclusion Allowing first order formulas in logic programs makes it easier and more ....

Sagonas, K., Swift, T., and Warren, D.S. XSB as an Efficient Deductive Database Engine. SUNY at Stony Brook, 1994.

....a partial evaluator, such as Mixtus [36] w.r.t. to a given program, P (written in L) yields compiled code for P . Provably correct compiled code is thus automatically obtained from the semantic specification. ffl By using a bottom up evaluation strategy (or a tabling based evaluation strategy [6,37]) the fixpoint of the denotation of a program written in L can be computed and used for verification purposes. ffl The postconditions and preconditions can be inserted in the program s Horn logical denotation and evaluated; by choosing a precondition carefully, and turning it into a generator, ....

....can be inserted in the program s Horn logical denotation and evaluated; by choosing a precondition carefully, and turning it into a generator, certain properties of interest of the program can be verified. ffl By using evaluation engines other than Prolog, such as those that are tabling based [6,37], and by choosing abstract semantics, abstract inter 3 preters [10] for a language L can be automatically obtained from the abstract semantic specification of L. ffl By choosing a suitable semantic algebra, and using partial evaluation, abstract machines can be derived and studied for the ....

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K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. In Proc. SIGMOD International Conf. on Management of Data, 1994.

.... they can be transformed into disjunctive extended logic programs as presented in [17] In consequence, any evaluation method for our logic programs with exceptions (e.g. by using an ad hoc evaluator 1 , or by transforming them to disjunctive extended logic programs 1 We implemented in XSB [26], EAnswers, our own evaluator for disjunctive extended logic programs with exceptions. 17] and evaluating those) can be combined with some standard evaluation method for first order queries (e.g. by translating them to relational algebra or SQL) to yield a method for evaluating K queries. ....

K. Sagonas, T. Swift, and D.S. Warren. XSB as an Efficient Deductive Database Engine. In Proc. ACM SIGMOD, 1994.

.... 2 5 Architecture In this section we give an outline of our prototype system ULTRA which is built on top of the deductive database system LOLA [ZF97] As the transaction processing is not integrated into the LOLA deduction engine, the LOLA system can be easily replaced by other systems, e.g. XSB [SSW94]. P IDB P UP D i i Q read access check isolation materialization processes materialize updates D EDB evaluation engine multi threaded Figure 3: Architecture of the ULTRA system The transactions invoked by top level update queries are processed in two phases: an evaluation ....

K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. In Proc. ACM SIGMOD Int. Conf. on Management of Data, pages 442--453, 1994.

....A modal semantics for our language can be developed to further understand its logical foundations, and to incorporate encapsulation. To demonstrate the feasibility of our language, we have implemented a variant of this language, called Datalog , on Unix and NT machines based on XSB [33, 32]. A web version of Datalog demo may be found at http: www.cs.msstate.edu jamil. Acknowledgments Research supported in part by a grant from the Department of Computer Science, Mississippi State University, and by the College of Engineering, Mississippi State University through a grant under ....

Konstantinos F. Sagonas, Terrance Swift, and David Scott Warren. Xsb as an efficient deductive database engine. In Richard T. Snodgrass and Marianne Winslett, editors, Proceedings of the ACM SIGMOD International Conference on Management of Data, Minneapolis, Minnesota, pages 442--453. ACM Press, 1994.

....for ffl based items induces the correctness of the evaluation with S 1 . We showed in [24] the equivalence of S 1 with the Magic Set based evaluations of logic programs [2] Memoization based algorithms: These have been proposed to evaluate the top down SLD strategy with tabulation [17,19,14]. For this strategy, the Magic Set techniques do not work because the information is not checked at return time. The memoization based algorithms try to remain as close as possible to a standard logic program evaluator by using a depth first evaluation with backtracking. However, they maintain a ....

K. Sagonas, T. Swift, and D.S. Warren. XSB as an efficient deductive database engine. In Proc. of SIGMOD'94 Conf. ACM, 1994.

....of both. Although the concept of tabled execution of logic programs has been around for more than a decade (see [27] practical systems based on tabling are only beginning to appear. Early experience with these systems suggests that they are indeed practically viable. In particular the XSB system [24], based on SLG resolution [3] computes in memory queries about an order of magnitude faster than current semi naive methods, and evaluates Prolog queries with little reduction in performance when compared to well known commercial Prolog systems. At a high level, top down tabling systems evaluate ....

....order. Consequently, in tabled programs which are not quasi terminating, nondeterminate unfolding (even without left propagation) can worsen their existential termination. This, in turn, might affect their behaviour under optimisations which involve pruning, such as existential negation (c.f. [24]) We illustrate the problem by the following example, which extends a similar example given in [21] Example 8. Assuming a scheduling strategy that returns answers to calls as soon as these are generated, program P of Figure 6 produces the answer X = 0 for the query p(X) and then loops, while ....

K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. In Proceedings of the ACM SIGMOD International Conference on the Management of Data, pages 442--453, Minneapolis, Minnesota, May 1994. ACM Press.

....on C# B E P if it does not map an infinite set of atoms of C to the same natural number. That is, partitions C into finite subsets. In particular, we have that every level mapping is finitely partitioning on a finite set C. 3. TABLING IN LOGIC PROGRAMS Our experience from the XSB system [Sagonas et al. 1994] is that tabled execution is used selectively in practice. Thus, before formally defining the resolution principle of tabling that we use, called SLG resolution, we first present some examples which motivate the need to freely mix LD resolution and tabled execution. 3.1 Mixing Tabled and LD ....

....Indeed, Prolog s evaluation strategy handles right recursion in grammars finitely. In fact, Prolog style evaluation of right recursion is more efficient than its tabled based evaluation: Prolog has linear complexity for a simple right recursive grammar, but with tabling implemented as in XSB [Sagonas et al. 1994] the evaluation could be quadratic as calls need to be recorded in the tables using explicit copying. Thus, it is important to allow tabled and nontabled predicates to be freely intermixed, and be able to choose the strategy that is most efficient for the situation at hand. By using tabling in ....

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SAGONAS, K., SWIFT,T.,AND WARREN, D. S. 1994. XSB as an efficient deductive database engine.

....1 ; Y 1 ) copy(Xn ; Yn ) and abstracting copy(X; Y ) as X Y does not work: The abstract success state of executing p(Y 1 ; Yn ) will update the abstractions of X 1 ; Xn . Our prototype binding time analyser currently consists of 800 lines of Prolog code and uses XSB [29] as a generic tool for semantic based program analysis [6] The boolean formulas from the POS domain are represented by their truth tables. This representation enables abstract operations to have straightforward implementations based on the projection and equi join operations of the relational ....

K. Sagonas, T. Swift, and D. S. Warren. XSB as an Efficient Deductive Database Engine. In Proceedings of the ACM SIGMOD International Conference on the Management of Data, pages 442--453, Minneapolis, Minnesota, May 1994. ACM.

....programming, to the context of tabled logic programming. In a companion paper [12] we describe how left propagation of bindings in a program executed under SLG resolution [4] using a fixed left to right computation rule (as SLG is usually implemented in practical tabled based systems such as XSB [15]) can seriously endanger the termination characteristics of that program. A simple example from [12] is the program p(X) p(Y ) Y = f(X) X = X For the query p(X) the program finitely fails in SLG since its left to right evaluation encounters (a variant of) an existing call for which no ....

K. Sagonas, T. Swift, and D. S. Warren. XSB as an Efficient Deductive Database Engine. In Proceedings of the ACM SIGMOD International Conference on the Management of Data, pages 442--453, Minneapolis, Minnesota, May 1994. ACM Press.

....dynamic code. CHAPTER 1. INTRODUCTION 4 ffl Object file compilation. ffl Module system and inference of symbol usage at compilation. ffl Dynamic loading of Prolog and C code. A goal of XSB is to provide in implementation engine for both logic programming and inmemory deductive database queries [27]. One prerequisite for this functionality is the ability to load a large amount of data very quickly. We have taken care to code in C a compiler for asserted clauses. The result is that the speed of asserting and retracting code is faster in XSB than in any other Prolog system that we know of. At ....

K. Sagonas, T. Swift, and D.S. Warren. XSB as an efficient deductive database engine. In Proc. of SIGMOD 1994 Conference. ACM, 1994.

....which conservatively extends the WAM [89] for SLG, computes in memory deductive database queries about an order of magnitude faster than other systems, and computes Prolog queries with little loss in efficiency over the WAM. The SLG WAM forms the engine for the XSB Logic Programming System [58, 59]. Version 1.4 of XSB has been tested on over a dozen hardware and operating system platforms 1 . The system has been installed in hundreds of sites in over 30 countries around the world. The performance of the SLG WAM is presented and analyzed in the third part of this dissertation. Comparisons ....

K. Sagonas, T. Swift, and D.S. Warren. XSB as an efficient deductive database engine. In Proc. of SIGMOD 1994 Conf. ACM, 1994.

....[24] 21] 32] 82] 53] 64] 134] 16] 13] 17] 18] 119] 110] 120] 136] Clear progress from Definite LPs, through Stratified and Normal LPs to Abductive LPs, Disjunctive LPs, and Quantitative LPs. Implementation and Systems [8] 129] 79] 49] 67] 98] 121] [109], 39] 9] 22] 51] 133] 99] 135] 101] 52] 42] 43] 54] 93] 107] 108] 31] XSB, YAP, Lola, and others Optimizations [36] 5 Overview ffl Magic Sets and Related Research (e.g. Alexander Method) Formulation [102] 7] 111] 124] 20] 87] 85] 10] 70] ....

K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. In ACM SIGMOD Conference, 1994.

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K. Sagonas, T. Swift, and D. Warren. Xsb as an efficient deductive database engine. In Proceedings of the 1994.

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Sagonas, K., Swift, T., and Warren, D. 1994. Xsb as an efficient deductive database engine. In Proceedings of the 1994 ACM SIGMOD International Conference on Management of Data. ACM Press, Minneapolis, MN, 442--453.

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Sagonas, K., Swift, T., & Warren, D. (1994). XSB as an efficient deductive database engine. ACM SIGMOD International Conference on Management of Data, San Jose, CA, pp. 442 -- 453.

No context found.

K. Sagonas, T. Swift, and D. S. Warren. Xsb as an efficient deductive database engine. In SIGMOD '94: Proceedings of the 1994 ACM SIGMOD International Conference on Management of Data, pages 442--453. ACM Press, 1994.

No context found.

K. F. Sagonas, T. Swift, and D. S. Warren. "XSB as an Efficient Deductive Database Engine." In Proceedings of the ACM International Conference on Management of Data (SIGMOD), 442--453. xxx: xxxx, 1994.

No context found.

K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. In Proceedings of the ACM SIGMOD International Conference on the Management of Data, pages 442--453, Minneapolis, Minnesota, May 1994.

No context found.

K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. pages 442--453, 1994.

No context found.

Sagonas, K., Swift, T., & Warren, D. (1994). XSB as an efficient deductive database engine. ACM SIGMOD International Conference on Management of Data, San Jose, CA, pp. 442 -- 453.

No context found.

K. F. Sagonas, T. Swift, and D. S. Warren. "XSB as an Efficient Deductive Database Engine." In Proceedings of the ACM International Conference on Management of Data (SIGMOD), 442--453. xxx: xxxx, 1994.

No context found.

K. F. Sagonas, T. Swift, and D. S. Warren. "XSB as an Efficient Deductive Database Engine." In Proceedings of the ACM International Conference on Management of Data (SIGMOD), 442--453. xxx: xxxx, 1994.

No context found.

Konstantinos Sagonas, Terrance Swift, and David S. Warren. XSB as an efficient deductive database engine. In Richard T. Snodgrass and Marianne Winslett, editors, Proc. of the 1994 ACM SIGMOD Int. Conf. on Management of Data (SIGMOD'94), pages 442--453, 1994. 29

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