M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K. Apt, editor, Proceedings of the International Joint Conference and Symposium on Logic Programming, Washington, 1992.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....Over the last two decades it has been applied on a number of di erent application domains, such as planning, diagnosis, multiagent coordination, However few of the implemented abductive systems were in general successful. Among the most evolved systems were the recent ACLP [2, 3] and SLDNFAC [1, 6], which combine constraint logic programming with abduction. In [4] a new system the A System is presented which adds to these systems a better control strategy, and can be seen as the descendant of both. Especially it adds a propagation phase after each choice the system makes. The result is a ....

Marc Denecker and Danny De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686-700. MIT Press, 1992.

....and an answer substitution such that D is consistent and entails all FOL axioms in T and 8( F ) An abductive procedure computes tables for the open predicates that can be extended in a unique way to a well founded model of the de nition, and a model of the FOL axioms and the query. SLDNFA (Denecker De Schreye 1992; 1998) is an abductive procedure for normal logic programs. The procedure sketched below is an extension of it to deal with FOL axioms and generalized rules and queries. As in the case of (Fung Kowalski 1997) and (Mantsivoda 1996) the procedure is proposed as a set of rewrite rules. A ....

Denecker, M., and De Schreye, D. 1992. SLDNFA; an abductive procedure for normal abductive programs. In Apt, K., ed., Proc. of the International Joint Conference and Symposium on Logic Programming, 686{ 700. MIT Press.

....the start of the 90s, a number of abductive systems were developed. In [54] the abductive procedure of [29] for computing negation as failure through abduction was extended to the case of general abductive predicates. Another early abductive procedure was developed in [10] using the completion. [17] proposed SLDNFA, an extension of SLDNF with abduction allowing nonground abductive hypotheses. 21] proposed an extension of SLDNFA with a constraint solver for linear order and demonstrated that this system could be applied correctly for partial order planning in the context of event calculus. ....

....Programming other semantics have been proposed as refinements of the completion semantics. These include the stable model semantics [38] and the well founded model semantics [116] The following ALP frameworks use these semantics for their underlying LP framework. SLDNFA and ID logic. SLDNFA [17, 20] is an abductive extension of SLDNFresolution [68] suitable for abductive reasoning in the context of (possibly recursive) abductive logic programs under the completion semantics. It was proven sound and, under certain restrictions, complete with respect to the 3 valued completion and ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686--700. MIT Press, 1992.

....unsuitable for many abductive computations. One is that it is only applicable to non recursive (sets of) de nitions; another one is that this algorithm does not provide integrated consistency checking of the generated answer formula. Improved implementations of i abduction are found in SLDNFA [9, 10] and the i procedure [16] Both algorithms can be seen as extensions of the SLDNFalgorithm [29] which provides the underlying procedural semantics for most current Prolog systems. We focus on SLDNFA. In what follows, we describe the answers generated by SLDNFA and its correctness results. In ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686-700. MIT Press, 1992.

....an answer substitution # such that D # is consistent and entails all FOL axioms in T and #(#(F ) An abductive procedure computes tables for the open predicates that can be extended in a unique way to a well founded model of the definition, and a model of the FOL axioms and the query. SLDNFA [5, 6] is an abductive procedure for normal logic programs. The procedure sketched below is an extension of it to deal with FOL axioms and generalised rules and queries. As in the case of [8] and [11] the procedure is proposed as a set of rewrite rules. The only syntactic restriction imposed on the FOL ....

Marc Denecker and Danny De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686--700. MIT Press, 1992.

....of general abductive predicates and later in [49, 53, 52] this was extended to incorporate constraint solving of CLP in a new framework called ACLP that integrates features of abductive and constraint logic programming. Another early abductive procedure was developed in [8] using the completion. [12] proposed SLDNFA, an extension of SLDNF with abduction allowing non ground abductive hypotheses. In [31] an abductive procedure that can be regarded as a hybrid between SLDNFA and the procedure of Console et al. has been de ned based on explicit rewrite rules with the completion and equality. This ....

.... nonmonotonic inheritance hierarchies [8, 19] and has been extended to characterize updates in deductive databases [10] The completion semantics is also the basis for the knowledge compilation optimization of abductive problem solving described in [9] SLDNFA and Open Logic Programming SLDNFA [12, 15] is an abductive extension of SLDNF resolution [59] suitable for abductive reasoning in the context of abductive logic programs under the completion semantics. This procedure came out of the early attempts to implement AI planning using abductive reasoning in the event calculus. Early experiments ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686-700. MIT Press, 1992.

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Benelog. Denecker, M., and De Schreye, D. 1992. SLDNFA; an abductive procedure for normal abductive programs. In Apt, K., ed., Proc. of the International Joint Conference and Symposium on Logic Programming, 686{

....stronger completeness results. The soundness of SLDNFA and its extensions is proven. Their completeness for minimal solutions with respect to implication, cardinality and set inclusion is investigated. The formalisation of SLDNFA presented here is an update of an older version presented in [13] and does not rely on skolemisation of abductive atoms. 1 Introduction The role of abduction [48] as a reasoning paradigm in AI is widely accepted. Abduction has been used for fault diagnosis [6] natural language understanding [6] default reasoning [22] 50] In the context of logic ....

....knowledge has been shown in the context of a translation from a temporal language A [27] to abductive logic programming. In the past, a number of abductive extensions of SLDNF resolution have been proposed for abductive logic programs with negation [21] 52] 46, 45, 44] 31] 8] 51] 29] [13], 54] Anticipating the discussion of these procedures in section 11, we can say that either these procedures have not been formalised and proven correct senior research associate of the Belgian National Fund for Scientific Research 1 [21] 52] or they can be proven correct only for a ....

[Article contains additional citation context not shown here]

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686--700, 1992.

....)g 4 Reasoning on open logic programs Traditionally, open programs have been associated with abduction as procedural paradigm. We show how other important procedural paradigms such as deduction and proving satisfiability are feasible and can be emulated by a suitable abduction procedure. In [6] we proposed SLDNFA, an abductive procedure for normal abductive programs. The soundness of SLDNFA has been proven. Two completeness results were proven: if an SLDNFA execution terminates with failure on a query Q, then comp a (PD ) j= 8( Q) hence no abductive solutions exist. If an SLDNFA ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686--700, 1992.

....constraints. That an abductive procedure can be used for explanation of some observation is well known from [21] It is less known that an abductive procedure can also be used for deduction and for proving consistency of a theory. In section 4, we apply the abductive procedure called SLDNFA [5, 6], to solve distinct computational tasks involving complete and incomplete knowledge. The paper is structured as follows. In section 2, we recall the language A and its semantics. In section 3, the transformation from A to situation calculus programs is presented and the soundness and completeness ....

....are feasible and can be emulated by a suitable abduction procedure. 1 Notice that the inconsistency of D3 can easily be repaired by dropping the fluent Off and replacing it everywhere by :On. It is unclear to us whether such a solution exists in general when the semantics of D and D differ. In [6] we proposed SLDNFA, an abductive procedure for normal abductive programs. The soundness of SLDNFA has been proven. Two completeness results were proven: if an SLDNFA execution terminates with failure on a query Q, then comp a (PD ) j= 8( Q) hence no abductive solutions exist. If an SLDNFA ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686--700, 1992.

....of this method has been implemented. An interesting experiment was its extension to an abductive planner based on the event calculus. Our prototype planner was able to solve some hard problems with context dependent events, problems that are not properly solved by existing systems [23] 22] In [7, 8], we proved the soundness of the procedure with respect to Completion semantics, in the sense that for any query Q and generated solution Delta: P Delta j= Q This implies the soundness of the procedure with respect to the Generalised Stable Model semantics of [14] a generated solution can ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686--700, 1992.

....in Rule (2.3) Since this is a positive goal, it should be executed abductively instead of deductively as is done in SLDNFA [Denecker Missiaen and B. 92] SLDNFA is sound with respect to the completion semantics and it generates at least all minimal solutions if the computation terminates [Denecker and De Schreye 92] However, the general abductive extension of negation by failure of SLDNFA results in an explosion of the search space. Powerful and intelligent control strategies will be required to make SLDNFA appropriate for solving practical planning problems. 5 Implementation of the abductive proof ....

Marc Denecker and Danny De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K. Apt, editor, Proceedings International Joint Conference and Symposium on Logic Programming, Washington, 1992.

....in the concept that facts change more often than rules and integrity constraints. On the level of practical applications, one might try to apply the methods of this paper to abductive and inductive logic programs. For instance, we conjecture that solvers for abduction, like the SLDNFA procedure [24], can greatly benefit in terms of efficiency, by generating specialised integrity checking procedures for each abducible predicate. Finally, it might also be investigated whether partial evaluation alone is able to derive specialised integrity checks. In other words, is it possible to obtain ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K. Apt, editor, Proceedings of the International Joint Conference and Symposium on Logic Programming, Washington, 1992.

....unsuitable for many abductive computations. One is that it is only applicable to non recursive (sets of) definitions; another one is that this algorithm does not provide integrated consistency checking of the generated answer formula. Improved implementations of iff abduction are found in SLDNFA [9, 10] and the iff procedure [15] Both algorithms can be seen as extensions of the SLDNFalgorithm [24] which provides the underlying procedural semantics for most current Prolog systems. We focus on SLDNFA; below, we describe the answers generated by SLDNFA and its correctness results. In section 3.1, ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686--700. MIT Press, 1992.

....An abductive procedure computes tables for the open predicates that can be extended in a unique way to a well founded model of the de nition and a model of the FOL axioms and of the query. This way, an abductive answer can be seen as a compact space ecient representation of a model. SLDNFA [7, 4] is an abductive procedure for normal logic programs. 9] describes an extension of this procedure to deal with FOL axioms and generalized rules and queries, and describes an integration of this procedure with constraint solvers. This integration is in a similar spirit as ACLP [14, 15] Due to ....

Marc Denecker and Danny De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686-700. MIT Press, 1992.

....and assertional information and to reason on open worlds. Moreover, the clear mapping between OLP and description logics allows to highlight the gain in knowledge representation power that OLP offers over these logics. Of course, the general problem solving procedures for OLP, such as SLDNFA ([9]) can not compete with the very efficient problem solvers developed in DL. A spinoff of the work reported in this paper is that it opens the opportunity to import efficient problem solving techniques from DLs to OLP, possibly by integrating the two formalisms. A possible gain for the DL community ....

....The correspondence between DLs and OLP is also visible at the procedural level. Typically abductive procedures based on resolution are used to reason on open logic programs, where DLs use special tableaux style algorithms. Here we describe the correspondence between the abductive procedure SLDNFA ([9]) and the procedure for consistency checking of ALCN theories described in [15] This algorithm does not consider the presence of a (nonempty) A Box, but it can be extended rather easily to deal with one. Most tasks studied in DLs can be reduced to checking if a certain concept C is satisfiable ....

[Article contains additional citation context not shown here]

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K. Apt, editor, Proceedings of the International Joint Conference and Symposium on Logic Programming, Washington, 1992.

....On the computational level, the project aims at developing the computational functionality of the knowledge base based on OLP FOL, and the design of the interface for the knowledge base. Currently, the work on this level is mainly concerned with the development of an abductive reasoner, SLDNFA [30], of which a prototype has been implemented. Abduction appears to be a very versatile reasoning paradigm, providing a rich functionality to a knowledge base with uncertainty. It has been used in AI diagnosis, for natural language interpretation, for temporal reasoning such as scheduling and ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686--700, 1992.

....an implementation of the A language of [10] in the Situation Calculus formulated as an abductive logic program. In this paper we demonstrate how a temporal database with incomplete information can be formalized in the Abductive Event Calculus and how a suitable abductive procedure like SLDNFA ([6]) which satisfies sufficiently strong sound and completeness results, can be used to implement the functionality of the database and to use the data for problem solving. Kowalski ( 13] has argued earlier that the Event Calculus in Logic Programming can be used to formalize the evolution of a ....

....the context of a temporal database. 3.1 The SLDNFA proof procedure There have been several attempts to build an abductive proof procedure and to use it in the context of temporal reasoning. Examples can be found in [8] 19] 17] and [11] In our proposal we use the SLDNFA procedure described in [6] and [7] This procedure, an extension of the SLDNF resolution of Logic Programming ( 12] 3] that can deal with abductive predicates, can handle deduction as well as abduction and allows for a correct treatment of non ground abducible atoms, which is necessary in our applications. Its ....

[Article contains additional citation context not shown here]

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K. Apt, editor, Proceedings of the International Joint Conference and Symposium on Logic Programming, Washington, 1992.

....In [8] we have shown how abductive extensions of SLDNF resolution, currently under development in the area of abductive logic programming, can be used for deduction, satisfiability checking and abduction in the context of open logic programming. We currently experimenting with the use of SLDNFA [6] for the above sorts of verification. The general applicability of Event Calculus to a wide range of tasks involving dynamic systems allows for an integration of protocol specifications with other systems. For example, in this paper we have specified a communication protocol. This protocol will ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686--700, 1992.

....sequence of actions necessary to prove the goal, which is the desired end state. In a similar way postdiction problems and indeterminism can be modeled. For our experiments we have used an implementation of the SLDNFA (SLD resolution with Negation as Failure and Abduction) procedure described in [ 6 ] and [ 7 ] This procedure allows for a better treatment of abducible atoms containing variables compared to other procedures. A proof of the soundness and completeness of the procedure with respect to Console completion semantics can be found in the aforementioned papers. An important feature of ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K. Apt, editor, Proceedings of the International Joint Conference and Symposium on Logic Programming, Washington, 1992.

....only for a restricted class of programs and formulas. In the next section, we show how in general any abductive, deductive or proof of consistency problem in the LP FOL formalism can be mapped to a problem that can be solved by SLDNFA. 5 Reasoning on normal queries wrt normal open programs In [5, 3] we proposed SLDNFA, an abductive procedure for solving normal queries wrt normal abductive programs. Here we will not be concerned with the procedural behavior of SLDNFA; for a description we refer to the aforementioned papers. Rather, we focus on the interface between SLDNFA and the declarative ....

....: F 0 : F n H : F 1 : F 00 : F n 1 The use of smaller is somewhat misleading: the substitution oe sk may map different abduced atoms of Delta 0 on the same atom in Delta; as a consequence, the cardinality of Delta may be strictly smaller than Delta 0 . In [5], a variant of SLDNFA has been defined which is more complete in the sense that it generates also the solutions with the smallest cardinality. ffl If F = 8X : F 0 , then substitute the following general clauses for Cl: H : F 1 : p(X 1 ; Xm ) F n p(X 1 ; Xm ) ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686--700, 1992.

....4 )g 4 Reasoning on open logic programs Traditionally, open programs have been associated with abduction as procedural paradigm. We show how other important procedural paradigms such as deduction and proving satisfiability are feasible and can be emulated by a suitable abduction procedure. In [6] we proposed SLDNFA, an abductive procedure for normal abductive programs. The soundness of SLDNFA has been proven. Two completeness results were proven: if an SLDNFA execution terminates with failure on a query Q, then comp a (PD ) j= 8( Q) hence no abductive solutions exist. If an SLDNFA ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K.R. Apt, editor, Proc. of the International Joint Conference and Symposium on Logic Programming, pages 686--700, 1992.

....system in order to obtain efficient update procedure compilers by self application. On the level of practical applications, one might try to apply the methods of this paper to abductive and inductive logic programs. For instance, we conjecture that solvers for abduction, like the SLDNFA procedure [21], can greatly benefit in terms of efficiency, by generating specialised integrity checking procedures for each abducible predicate. Finally, it might also be investigated whether partial evaluation alone is able to derive specialised integrity checks. In other words, is it possible to obtain ....

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K. Apt, editor, Proceedings of the International Joint Conference and Symposium on Logic Programming, Washington, 1992.

No context found.

M. Denecker and D. De Schreye. SLDNFA; an abductive procedure for normal abductive programs. In K. Apt, editor, Proceedings of the International Joint Conference and Symposium on Logic Programming, Washington, 1992.

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