Eshghi, Kave, & Kowalski, Robert A. (1989). Abduction compared with negation as failure. Proceedings of the 6th. international conference on logic programming. Lisbon, Portugal: MIT Press.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....and Hayes identi ed actions with imperative programs. Later, the trend moved toward more abstract formalisms, in which actions are abstract entities subject to characterization within a logical framework. Today, the latter approach, often based on logic programming with negation as failure ([9]) seems to underlie most of the work in the area. The aim of this paper is to present a formal system which comprises the following components. A logic to describe and to reason about changes of the world. A language to de ne actions. A logical framework whose judgments relate actions ....

Eshghi, K., and R. Kowalski. Abduction compared with negation as failure. In G. Levi and M. Martelli (Eds.) Logic programming: Proc. 6th Int'l Conf., 1989, pp. 234-255.

....and Hayes identified actions with imperative programs. Later, the trend moved toward more abstract formalisms, in which actions are abstract entities subject to characterization within a logical framework. Today, the latter approach, often based on logic programming with negation as failure ([10]) seems to underly most of the work in the area. The aim of this paper is to present a formal system which comprises the following components. A logic to describe and to reason about changes of the world. A language to define actions. A logical framework whose judgments relate actions ....

Eshghi, K., and R. Kowalski. Abduction compared with negation as failure. In G. Levi and M. Martelli (Eds.) Logic programming: Proc. 6th Int'l Conf., 1989, pp. 234--255.

....fixed. LP is the instance of the abstract framework hT; A; i where T is a logic program, the assumptions in A are all negations not p of atomic sentences p, and the contrary not p of an assumption is p. is Horn logic provability, with assumptions, not p, understood as new atoms p , as in [12]. DL is the instance of the abstract framework hT; A; i where the monotonic logic is first order logic augmented with domain specific inference rules of the form 1 ; m ; M 1 ; M n where i ; j ; are sentences in classical logic. T is a classical theory and A ....

Kave Eshghi and Robert A. Kowalski. Abduction compared with negation as failure. In G. Levi and M. Martelli, editors, Proceedings of the 6th International Conference on Logic Programming, pages 234--254, Lisbon, Portugal, 1989. MIT Press.

....to address some of the limitations of deductive reasoning in classical logic. The role of abduction has been demonstrated in a variety of applications. It has been proposed as a reasoning paradigm in AI for diagnosis [8, 90] natural language understanding [8, 39, 4, 93] default reasoning [81, 29, 25, 50], planning [28, 110, 71, 59] knowledge assimilation and belief revision [54, 76] multi agent systems [7, 64, 102] and other problems. In the context of logic programming, the study of abductive inference started at the end of the eighties as an outcome of di#erent attempts to use logic ....

....The application of abduction to diagnosis has been studied in [10, 11] within an abductive logic programming framework whose semantics was defined by a suitable extension of the completion semantics of LP. In parallel to these studies of abduction as an inferential method, Eshghi and Kowalski [29] and later Kakas and Mancarella in [52, 54] and Dung in [25] used abduction as a semantical device to describe the non monotonic semantics of Logic Programming (in a way analogous to Poole in [81] In [18, 14] abductive logic programming was investigated from a knowledge representation point of ....

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K. Eshghi and R.A. Kowalski. Abduction compared with negation as failure. In Proc. of the International Conference on Logic Programming. MIT-press, 1989.

....also applications of integration of abduction and constraint programming for reasoning in continuous change applications and resource planning. 1 Introduction Abduction has been proposed as a reasoning paradigm in AI for fault diagnosis [4] natural language understanding [4] default reasoning [15], 39] In the context of logic programming, abductive procedures have been used for planning [14] 48] 35, 34] knowledge assimilation and belief revision [23] 21] database updating [22] 11] showed the role of an abductive system for forms of reasoning, di erent from planning, in the ....

K. Eshghi and R.A. Kowalski. Abduction compared with negation as failure. In Proc. of the International Conference on Logic Programming. MIT-Press, 1989.

....of capturing inheritance reasoning in full. Recently, You et al. 59] presented a polynomial translation from defeasible inheritance networks into equivalent logic programs. They showed that a well known query answering procedure in logic programming, the Eshghi and Kowalski proof procedure [16], can be used to compute the credulous semantics of inheritance networks. Theorem 8 proves that a similar result can be achieved for general inheritance networks. Here, we advocate the use of well known algorithms for computing extensions of Reiter s default theories to compute the entailment ....

K. Eshghi and R. Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proceedings of the Sixth International Conf., pages 234-255, 1989.

....existence of stable models, in many cases when the Herbrand base is in nite, but the set of unde ned atoms is nite. This may be useful for any procedural semantics based on stable models. We will outline in fact how the method can help ensure correctness of the abductive procedure introduced in [4] also on non locally strati ed programs. After Section 2, which reports some useful de nitions, in Section 3 we introduce the new criterion for checking stability of a minimal model, called test. In Section 4 we show that any method for calculating the well founded model can be used for ....

....of our knowledge, the weakest condition ever stated in the literature for computing or characterizing the stable model semantics. Finally, we discuss how the characterization of stable models via s generators is related to the sets of abductive hypotheses and the abductive procedure introduced in [4]. 2 Preliminary De nitions and Observations In the rest of this paper we will consider general programs, i.e. Horn clause programs with negation. As base reference for semantics of general logic programs we take [15] which is entirely devoted to a systematic exposition and comparison of the ....

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K. Eshghi and R.A. Kowalski. Abduction Compared with Negation as Failure. G. Levi and M. Martelli (eds.), Logic Programming, Proceedings of the Sixth International Conference. The MIT Press, 1989.

....to address some of the limitations of deductive reasoning in classical logic. The role of abduction has been demonstrated in a variety of applications. It has been proposed as a reasoning paradigm in AI for diagnosis [6, 79] natural language understanding [6, 33, 3, 81] default reasoning [70, 24, 20, 43], planning [23, 97, 61, 51] knowledge assimilation and belief revision [47, 65] multi agent coordination [5, 55] and other problems. In the context of logic programming, the study of abductive inference started at the end of the eighties as an outcome of di erent attempts to use logic ....

....48] The application of abduction to diagnosis has been studied in [8, 9] within an abductive logic programming framework whose semantics was de ned by a suitable extension of the completion semantics of LP. In parallel to these studies of abduction as an inferential method, Eshghi and Kowalski [24] and later Kakas and Mancarella in [45, 47] and Dung in [20] used abduction as a semantical device to describe the non monotonic semantics of Logic Programming (in a way analogous to Poole in [70] In [13, 11] abductive logic programming was investigated from a knowledge representation point of ....

[Article contains additional citation context not shown here]

K. Eshghi and R.A. Kowalski. Abduction compared with negation as failure. In Proc. of the International Conference on Logic Programming. MITpress, 1989.

....to represent the frame axiom correctly. A nonmonotonic reasoning technique that was mistakenly not considered by these authors is negation as failure. It has been shown that the YTS representation in situation calculus or event calculus with negation as failure solves the problem correctly ( 1] [4], 5] Negation as failure alone is not sufficient for representing many temporal reasoning problems. A major restriction is its incapacity of representing incomplete knowledge. The original event calculus only supports the prediction of a goal state, starting from a complete description of the ....

K. Eshghi and R.A. Kowalski. Abduction compared with negation as failure. In Proc. of the International Conference on Logic Programming. MITpress, 1989.

....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 programming, abductive procedures have been used for planning [21] 52] 46, 44] knowledge assimilation and belief revision [32] 30] database updating [31] 18] showed the role of an abductive system for forms of reasoning, different from planning, in the ....

....holds. Section 6 is devoted to a discussion of the answers that can be derived from an SLDNFA refutation. Second, it turns out that our techniques for solving the floundering abduction problem (using variables) allow also to provide a partial solution for the floundering negation problem. In [22], an abductive interpretation of negation in logic programs was proposed. In this view, negative calls are seen as a special kind of abductive calls. As observed in [31] this entails that a solution for the floundering negation problem also provides a solution for the floundering abduction ....

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K. Eshghi and R.A. Kowalski. Abduction compared with negation as failure. In Proc. of the International Conference on Logic Programming. MIT-press, 1989.

....at frameworks. This class includes logic programming with negation as failure and default logic. We de ne all proof procedures parametrically with respect to a proof procedure computing the semantics of admissible extensions. A number of such procedures have been proposed in the literature, e.g. [8, 4, 6, 7, 13]. We argue that the proof procedures for reasoning under the preferred extension semantics are simpler than those for reasoning under the stable extension semantics. This is an interesting argument in that, in many meaningful cases (e.g. when the frameworks are order consistent [1] the proof ....

....programming is the instance of the abstract framework hT ; Ab; i where T is a logic program, the assumptions in Ab are all negations not p of atomic sentences p, and the contrary not p of an assumption is p. is Horn logic provability, with assumptions, not p, understood as new atoms, p (see [8]) The logic programming semantics of stable models [9] admissible scenaria [4] and partial stable models [21] preferred extensions [4] correspond to the semantics of stable, admissible and preferred extensions, respectively, of the instance of the abstract framework for logic programming [1] ....

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K. Eshghi, R. A. Kowalski, Abduction compared with negation as failure. Proceedings of the 6th International Conference on Logic Programming, Lisbon, Portugal (1989), MIT Press (G. Levi and M. Martelli, eds) 234-254

....[2] for logic programming. The proof procedure is sound but incomplete. We employ the credulous proof procedure to de ne a sound sceptical proof procedure, adapting the results of [16] We compare the resulting proof procedures with others, computing the same semantics, notably the ones in [5, 2, 16]. 1 Introduction In [1] we have shown that many formalisms for default reasoning [10, 14, 11, 12] can be understood as special cases of a single abstract framework, based upon Theorist [13] and an abductive interpretation of the semantics of logic programming [5] In the framework, default ....

.... notably the ones in [5, 2, 16] 1 Introduction In [1] we have shown that many formalisms for default reasoning [10, 14, 11, 12] can be understood as special cases of a single abstract framework, based upon Theorist [13] and an abductive interpretation of the semantics of logic programming [5]. In the framework, default reasoning in general is understood as extending a theory formulated in a monotonic logic by a defeasible set of assumptions. An assumption can be defeated (or attacked ) if its contrary can be proved, possibly with the aid of other con icting as1 sumptions. We have ....

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K. Eshghi, R. A. Kowalski, Abduction compared with negation as failure. Proceedings of the 6th International Conference on Logic Programming, Lisbon, Portugal (1989), MIT Press (G. Levi and M. Martelli, eds) 234-254

.... and has been used in various AI applications [PMG98,Poo89] including: temporal explanations [Sha89,DMB92,Sha93] diagnosis [Reg83,Rei87] planning [Esh88,AKPT91,MD95] natural language understanding [HSAM90] Preprint submitted to Elsevier Science 9 March 2000 default reasoning [PGA87,Poo88a,EK89,KKT93] belief revision and updates [BB95,Bou96] and formulation of negation as failure [EK89,KKT93] Although, abduction is often used as a backward reasoning method where observations are explained, we can also do forward reasoning using abduction. This happens when, certain new ....

.... [Sha89,DMB92,Sha93] diagnosis [Reg83,Rei87] planning [Esh88,AKPT91,MD95] natural language understanding [HSAM90] Preprint submitted to Elsevier Science 9 March 2000 default reasoning [PGA87,Poo88a,EK89,KKT93] belief revision and updates [BB95,Bou96] and formulation of negation as failure [EK89,KKT93] Although, abduction is often used as a backward reasoning method where observations are explained, we can also do forward reasoning using abduction. This happens when, certain new conclusions are entailed by each of the explanations 1 (or each of the preferred explanations) of an ....

K. Eshghi and R. Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

....Dupr e and Torasso in [14] analyze abductive problems hH; M;LP; j=i where LP is a hierarchical (i.e. non recursive) program and j= is the entailment operator based on Clark s program completion. The relation of abduction to negation as failure has been investigated by Eshghi and Kowalski [22], Inoue [29] and Iwayama and Satoh [32] respectively. Under some syntactic conditions, a 1 1 correspondence between the solutions of an abductive problem and the answer sets of an extended logic program obtained from it has been proven. In a recent work [4] Baral and Gelfond define a notion of ....

....In some sense their approach is similar to LPAPs of the form hH; M;LP; j= c st i, but they impose stronger conditions. An important bunch of work on abductive logic programming concerns the definition of abductive procedures, which compute an abductive explanation of a given manifestation [22, 35, 32, 70, 15, 17, 7]. 37 The seminal work in this area is due to Eshghi and Kowalski [22] who consider abduction based on stable model semantics and provide a proof procedure to compute an abductive solution. This procedure has been then extended by Kakas and Mancarella to manipulate arbitrary abducibles. Both ....

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K. Eshghi and R. Kowalski. Abduction Compared with Negation as Failure. In Proc. ICLP '89, pp. 234--254. MIT Press, 1989.

....in Charniak and Mc Dermott [10] where the most probable inferred hypothesis is assumed to be the best, we adopt a qualitative evaluation schema. We notice that such an approach, already present in Peirce [4] has been adopted in Hintikka [15] Reggia et al. 18] Reiter [20] Eshghi and Kowalski [14] and in Burattini et al. 5] 6] who reject probabilistic or numerical constructs. With the term prediction we indicate a mode of inference in which the antecedent of the rule is only supposed to be true and, in this case, also the conclusion of the rule is supposed to be true. This inference is ....

Eshghi K., Kowalski R.A., Abduction compared with negation as failure, Proc. 6 th International Conference on Logic Programming, Lisbon, Portugal, (1989) 234255.

....defeasible and abnormal effects. Our goal is to handle these three types of defeasibilities in reasoning about action under a framework of logic programming. The issue of representing action properties in logic programming languages is not new. It was explored by some researchers previously, e.g. [5, 6]. However, probably Gelfond 1 Informally, A ) B represents a semantics like if A then B, from which we cannot derive :B ) A. See [17] for detail. 4 and Lifschitz s work [9] was the first time to make major progress in this issue. By introducing a simple action language A, Gelfond and ....

Eshghi, K. and Kowalski, R., Abduction compared with negation as failure. In Proceedings of the Sixth International Conference on Logic Programming, pp234255. MIT Press, 1989.

....of the programs from [Tur94] DDS93] HT93] Dun93] Since these formalizations use different languages with different semantics, establishing this fact directly, without the use of A and AC , will be probably more difficult. Before A was introduced there were several works (which includes [AB90, EK89, Eva89]) that reasoned about actions using logic programs. In [AB90] Apt and Bezem consider the 16 case when there is complete information about the initial situation. If we consider only such domain descriptions then our f is an extension of Apt and Bezem s formalization. This can be easily shown ....

....relations. Future research will show if this is a right assessment. The second theme of the paper is centered around the question of applicability of logic programming languages to representing knowledge about actions. The early attempts on such representation include Eshghi and Kowalski [EK89], Evans [Eva89] Apt and Bezem [AB90] among others. These formalizations used the language of general logic programs and therefore assumed the closed world assumption about all predicates. Formalization in the language of extended logic programs which has no such limitation was suggested in ....

K. Eshghi and R. Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989. 23

....applications of integrations of abduction and constraint programming for reasoning in continuous change applications and ressource planning. 1 Introduction Abduction has been proposed as a reasoning paradigm in AI for fault diagnosis [4] natural language understanding [4] default reasoning [14], 34] In the context of logic programming, abductive procedures have been used for planning [13] 43] 31, 29] knowledge assimilation and belief revision [21] 19] database updating [20] 11] showed the role of an abductive system for forms of reasoning, different from planning, in the ....

K. Eshghi and R.A. Kowalski. Abduction compared with negation as failure. In Proc. of the International Conference on Logic Programming. MIT-press, 1989.

....is an implementation of the proof theory presented in (Kakas, Miller, Toni 1999) but it does not rely explicitly on tree derivations. Instead, it implicitly manipulates trees via their frontiers, in a way similar to the proof procedure for computing partial stable models of logic programs in (Eshghi Kowalski 1989; Kakas Mancarella 1990) See also (Kakas Toni 1999) for a general discussion of this technique. E RES de nes the Prolog predicates sceptical 1 and credulous 1. For some given Goal which is a list of literals, with each literal either of the form holds(f,t) or neg(holds(f,t) where the ....

Eshghi, K., and Kowalski, R. 1989. Abduction compared with negation as failure. In ICLP'89, MIT Press.

....y 4 is not stratified it is possible to show (see Theorem 2.5) that it has a unique stable model. From this and Lemma 2. 4 it is easy to see that Y entails holds(alive; res(load; s 0 ) and :holds(alive; res(shoot; res(wait; res(load; s 0 ) 2 As we can see, the logic programming solution [Eva89, AB91, EK89] to the original Yale Shooting Problem is rather natural and simple. This is not, of course, to say that it can be easily generalized to more complicated forms of reasoning about actions. It is worth recalling that the original formulations of this story in the formalisms of circumscription and ....

....though sound [Cla78] is only complete for a subclass of stratified programs [JLL83] Various practical Prolog systems have been developed based on SLDNF resolution. To answer queries with respect to programs with a multiple number of stable models, several approaches have been suggested [PAA91a, BNNS94, FLMS93, SZ90, IKH92, WC93, EK89] in the literature. Warren s XOLDT resolution uses a combination of bottom up 5 A set is recursive if its characteristic function is recursive. 6 Intuitively, we say A flounders with respect to Pi if while proving A from Pi using SLDNF derivation a goal is reached which contains only ....

[Article contains additional citation context not shown here]

K. Eshghi and R. Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

....procedures developed in this paper are directly applicable to the nonpropositional ( rst order) form of the logic program, similarly to SLDNF. The origin and motivation of the proof theories and procedures we propose can be traced back to the seminal abductive proof procedure for LP presented in [14]. The speci c proof theories and procedures for computing partial stable models, stable theories and acceptability generalise the procedure in [14] in the sense that whatever is computed by this is also computed by our proof procedures for these semantics. Since the procedure of [14] is a ....

.... origin and motivation of the proof theories and procedures we propose can be traced back to the seminal abductive proof procedure for LP presented in [14] The speci c proof theories and procedures for computing partial stable models, stable theories and acceptability generalise the procedure in [14] in the sense that whatever is computed by this is also computed by our proof procedures for these semantics. Since the procedure of [14] is a generalisation of SLDNF, in the same sense, so are our proof procedures. The proof procedure for computing the well founded model semantics is also a ....

[Article contains additional citation context not shown here]

K. Eshghi, R. A. Kowalski. Abduction compared with negation as failure. Proceedings of the 6th International Conference on Logic Programming, Lisbon, Portugal (1989) MIT Press (G. Levi and M. Martelli, eds) 234-254

.... concentration of such work has been in circumscription [Hau87, Lif87a, LR89, Lif90, Bak91, GLR91, Lif91, LS91, CE92, LR94, KL95, Lin95, Gus96, Lin96] There were also early published solutions to the Yale Shooting problem in autoepistemic logic [Gel88] default logic [Mor88] and logic programming [EK89, Eva89, AB90]. A primary methodological weakness of much of the work cited above is the fact that it is motivated by, and validated for, only a small set of examples. In many cases, there is no clear claim about what kinds of action domains can be represented correctly by a given approach. Moreover, it is ....

Kave Eshghi and Robert Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

.... reasoning about the effects of actions can be automated using SLG, a logic programming interpreter based on SLG resolution, developed by Chen and Warren [1993a,1993b] Formalizations of action based on the situation calculus and logic programming with negation as failure were first introduced by Eshghi and Kowalski [1989] and Evans [1989] These logic programs are closely related to some formalizations that use default logic [ Morris, 1988 ] and autoepistemic logic [ Gelfond, 1989 ] Apt and Bezem [1990] observed that such programs are acyclic, which implies that the SLDNF procedure will terminate for them on ....

Kave Eshghi and Robert Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

.... beginning of the century and has been used in various AI applications [PMG98] including: temporal explanations [Sha89,DMB92,Sha93] diagnosis [Reg83,Rei87] planning [Esh88,AKPT91,MD95] natural language understanding [HSAM90] Preprint submitted to Elsevier Science 4 April default reasoning [PGA87,Poo88,EK89,KKT93], belief revision and updates [BB95,Bou96] and formulation of negation as failure [EK89,KKT93] Although, abduction is often used as a backward reasoning method where observations are explained, we can also do forward reasoning with abduction. This happens when, certain new conclusions are ....

.... [Sha89,DMB92,Sha93] diagnosis [Reg83,Rei87] planning [Esh88,AKPT91,MD95] natural language understanding [HSAM90] Preprint submitted to Elsevier Science 4 April default reasoning [PGA87,Poo88,EK89,KKT93] belief revision and updates [BB95,Bou96] and formulation of negation as failure [EK89,KKT93]. Although, abduction is often used as a backward reasoning method where observations are explained, we can also do forward reasoning with abduction. This happens when, certain new conclusions are entailed by each of the explanations (or each of the preferred explanations) of an observation ....

K. Eshghi and R. Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

....also be viewed as a procedure for generating abductive inferences. To see this, note that an expansion of the predicates in could be viewed as an explanation of in terms of the definitions in R. Under this interpretation, the goal OE plays the role of a negative integrity constraint [ Eshghi and Kowalski, 1989; Kakas and Mancerella, 1990 ] i.e. a sentence that must be false in the abductive explanation. If n integrity constraints :I 1 ; In must be satisfied, constructing an abductive explanation of corresponds to finding a countermodel for the relation Circ(R(P ) P ) j= OE( where OE = ....

K. Eshghi and R. Kowalski. Abduction compared with negation as failure. In G. Levi and M. Martelli, editors, Logic Programming: Proceedings of the Sixth International Conference, pages 234--254, Boston, MA, 1989. MIT Press.

....The method is applicable to temporal projection problems with incomplete information, as well as to reasoning about the past. It is proved to be sound relative to a semantics of action based on states and transition functions. 1 Introduction This paper extends the work of Eshghi and Kowalski [6], Evans [7] and Apt and Bezem [1] on representing properties of actions in logic programming languages with negation as failure. Our goal is to overcome some of the limitations of the earlier work. The existing formalizations of action in logic programming are adequate for only the simplest kind ....

Kave Eshghi and Robert Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

....y 4 is not stratified it is possible to show (see Theorem 2.5) that it has a unique stable model. From this and Lemma 2. 4 it is easy to see that Y entails holds(alive; res(load; s 0 ) and :holds(alive; res(shoot; res(wait; res(load; s 0 ) 2 As we can see, the logic programming solution [Eva89, AB91, EK89] to the original Yale Shooting Problem is rather natural and simple. This is not, of course, to say that it can be easily generalized to more complicated forms of reasoning about actions. It is worth recalling that the original formulations of this story in the formalisms of circumscription and ....

....though sound [Cla78] is only complete for a subclass of stratified programs [JLL83] Various practical Prolog systems have been developed based on SLDNF resolution. To answer queries with respect to programs with a multiple number of stable models, several approaches have been suggested [PAA91a, BNNS94, FLMS93, SZ90, IKH92, WC93, EK89] in the literature. Warren s XOLDT resolution uses a combination of bottom up and top down methods. Bell et al. BNNS94] present an approach to compute the stable models by constructing a linear programming problem from the program and solving the linear programming problem. In [Esg90] PC89] ....

[Article contains additional citation context not shown here]

K. Eshghi and R. Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

....of the programs from [Tur94] DDS93] HT93] Dun93] Since these formalizations use different languages with different semantics, establishing this fact directly, without the use of A and AC , will be probably more difficult. Before A was introduced there were several works (which includes [AB90, EK89, Eva89]) that reasoned about actions using logic programs. In [AB90] Apt and Bezem consider the case when there is complete information about the initial situation. If we consider only such domain descriptions then our f is an extension of Apt and Bezem s formalization. This can be easily shown ....

....relations. Future research will show if this is a right assessment. The second theme of the paper is centered around the question of applicability of logic programming languages to representing knowledge about actions. The early attempts on such representation include Eshghi and Kowalski [EK89], Evans [Eva89] Apt and Bezem [AB90] among others. These formalizations used the language of general logic programs and therefore assumed the closed world assumption about all predicates. Formalization in the language of extended logic programs which has no such limitation was suggested in ....

K. Eshghi and R. Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

....logics. A particularly striking example can be found in research on the frame problem. It is known that expressing temporal persistence by the formula Holds(f; s) Ab(f; a; s) oe Holds(f; Result(a; s) leads to difficulties [ Hanks and McDermott, 1987 ] This fact prompted several authors ( Eshghi and Kowalski, 1989 ] Evans, 1989 ] Apt and Bezem, 1990 ] to experiment with the corresponding logic programming rule Holds(f; Result(a; s) Holds(f; s) not Ab(f; a; s) 2) Independently, Morris [1988] proposed to express the same principle of reasoning by the default Holds(f; s) Ab(f; a; s) ....

Kave Eshghi and Robert Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

....under consideration. 1 Introduction Negation as failure and abduction have been recognized as important forms of non monotonic reasoning [23] 4] 36] They have been shown useful for fault diagnosis [4] natural language understanding [4] knowledge assimilation [20] and default reasoning [14], 36] Here we present a technical contribution to the area. We present a general procedure for logic programs which integrates both negation as failure and abduction. This procedure resulted from research in the domain of temporal reasoning. Temporal reasoning is an excellent domain for testing ....

.... Diensten voor Programmatie van Wetenschapsbeleid , under the contract RFO AI 03, and by ESPRIT BRA Compulog II under contract 6810 y supported by the Belgian National Fund for Scientific Research been shown that the YTS representation in these formalisms solves the problem correctly [1] [14], 15] Negation as failure alone is not sufficient for representing many temporal reasoning problems. A major restriction is its inability of representing incomplete knowledge. The original event calculus only supports the prediction of a goal state, starting from a complete description of the ....

K. Eshghi and R.A. Kowalski. Abduction compared with negation as failure. In Proc. of the International Conference on Logic Programming. MIT-press, 1989.

...., we will need to distinguish between proposals of several kinds, differing by the choice of the underlying logic. Some of them combine the situation calculus with classical logic (for instance, Schubert, 1990 ] Reiter, 1991 ] Elkan, 1992 ] some with logic programming (for instance, Eshghi and Kowalski, 1989 ] Evans, 1989 ] Apt and Bezem, 1990 ] some with circumscription (for instance, Haugh, 1987 ] Lifschitz, 1987 ] Baker, 1989 ] or with other nonmonotonic formalisms (for instance, Morris, 1988 ] and [ Gelfond, 1989 ] Some of the more recent work on representing action ....

Kave Eshghi and Robert Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

....The pilgrim has two guns, and at least one of them is initially loaded. The turkey is initially alive. The available actions are loading and shooting. We are interested in representing this action domain using the situation calculus and negation as failure. Early work of this kind is described in [EK89], Eva89] AB90] and [Gel91] The subject is treated more systematically in several recent papers, including [GL93] DDS93] and [Dun93] We assume that the reader is familiar with the main ideas of this work. The following formulation of the two gun example is close to the one proposed in ....

Kave Eshghi and Robert Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

.... for acceptability is a generalisation of proof theories and procedures for (sound) approximations of the acceptability semantics such as preferred extensions [3] and stable theories [8] which are in turn a generalisation of the Eshghi Kowalski (E K) abductive proof procedure presented in [5]. In fact, for clarity of presentation, we will first give, in sections 3 and 4, the computational framework for the special cases of the preferred extension and stable theory semantics, and then show, in sections 5 and 6, how these need to be extended to capture the full acceptability semantics. ....

....the set fnot p j p is a variable free atom in the Herbrand base of Pg, and the monotonic background logic is the classical logic of definite Horn programs. These programs are obtained by replacing each negation as failure literal in the program P and in the hypotheses set H by a new positive atom [5]. We will denote these programs by the same symbol P , and the consequence relation of this logic by j= Unless otherwise specified, we will assume that programs containing variables represent the set of all their variable free instances over the given Herbrand universe. The notion of attack ....

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K. Eshghi, R. A. Kowalski, Abduction compared with negation as failure. ICLP`89

.... in particular in the area of nonmonotonic reasoning [ Ginsberg, 1987, Reiter, 1987a ] default reasoning [ Poole, 1989, Selman and Levesque, 1990 ] and truth maintenance systems [ Reiter and de Kleer, 1987 ] autoepistemic logic [ Levesque, 1989 ] negation as failure in logic programming [ Eshghi and Kowalski, 1989 ] deductive database updates [ Kakas and Mancarella, 1990 ] The complementarity of predictive and abductive reasoning has been considered not only in the logical approaches to AI [ Poole, 1989, Shanahan, 1989 ] but also in the probabilistic ones [ Pearl, 1987 ] Formal studies on abductive ....

....rule is clearly unsound from the deductive point of view and this shows the fundamental difference between abduction and deduction. The characterization of abductive explanation in terms of deduction reported above (which is similar to the ones in [ Cox and Pietrzykowski, 1987, Poole et al. 1987, Eshghi and Kowalski, 1989 ] can be regarded as a meta level one since it defines explanations with a condition mentioning the deductive consequence relation. In this chapter an alternative characterization is proposed, showing how the conclusions of abductive reasoning can be derived deductively at the object level, ....

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Eshghi, K. and Kowalski, R. 1989. Abduction compared with negation as failure. In Proc. 6th Int. Conf. on Logic Programming, Lisbon. MIT Press. 234--254.

....planning strategies. In the second part of the paper, in particular, we have shown how to support partially ordered plans and optimization using systematicity. Several works have addressed the problem of modeling the logic of actions by means of logic programming languages. Eshgi and Kowalski [13], and Evans [14] showed how negation by failure can be successfully employed to correctly formalize the so called Yale shooting problem [18] Apt and Bezem [2] further elaborated that the Yale Shooting Problem (YSP) as well as some other temporal reasoning problems, can be modeled by means of a ....

K. Eshgi and R.A. Kowalski. Abduction compared with negation as failure. In G. Levi and M. Martelli, editors, Proceedings Sixth International Conference on Logic Programming, pages 234--254. The MIT Press, 1989.

.... the highest probability [98] and minimality of the set of abnormal components [110] Most closely related to our work in this chapter are the logic programming formulations of abduction, which note that explanations may be obtained as the dead ends of attempted linear resolution refutations [103, 26, 34]. These authors frequently consider the abduced explanation as suggesting a discriminating experiment which will generate further information. Thus, in some sense they take a sceptical attitude. The inference problem we study corresponds to the sceptical attitude to abduction, in that we accept ....

K. Eshghi and R. Kowalski. Abduction compared with negation as failure. In G. Levi and M. Martelli, editors, Logic Programming: Proceedings of the Sixth International Conference, pages 234--254, Boston, MA, 1989. The MIT Press.

....procedures developed in this paper are directly applicable to the nonpropositional (first order) form of the logic program, similarly to SLDNF. The origin and motivation of the proof theories and procedures we propose can be traced back to the seminal abductive proof procedure for LP presented in [14]. The specific proof theories and procedures for computing partial stable models, stable theories and acceptability generalise the procedure in [14] in the sense that whatever is computed by this is also computed by our proof procedures for these semantics. Since the procedure of [14] is a ....

.... origin and motivation of the proof theories and procedures we propose can be traced back to the seminal abductive proof procedure for LP presented in [14] The specific proof theories and procedures for computing partial stable models, stable theories and acceptability generalise the procedure in [14] in the sense that whatever is computed by this is also computed by our proof procedures for these semantics. Since the procedure of [14] is a generalisation of SLDNF, in the same sense, so are our proof procedures. The proof procedure for computing the well founded model semantics is also a ....

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K. Eshghi, R. A. Kowalski. Abduction compared with negation as failure. Proceedings of the 6th International Conference on Logic Programming, Lisbon, Portugal (1989) MIT Press (G. Levi and M. Martelli, eds) 234-254

....The method is applicable to temporal projection problems with incomplete information, as well as to reasoning about the past. It is proved to be sound relative to a semantics of action based on states and transition functions. 1 Introduction This paper extends the work of Eshghi and Kowalski [6], Evans [7] and Apt and Bezem [1] on representing properties of actions in logic programming languages with negation as failure. Our goal is to overcome some of the limitations of the earlier work. The existing formalizations of action in logic programming are adequate for only the simplest kind ....

Kave Eshghi and Robert Kowalski. Abduction compared with negation as failure. In Giorgio Levi and Maurizio Martelli, editors, Logic Programming: Proc. of the Sixth Int'l Conf., pages 234--255, 1989.

....we do not address in this paper but is useful to consider for the application of abduction to non monotonic reasoning such as planning and database updates, is the management of negation [Bid91] Several semantics and procedures have been developed to handle this problem. We refer the reader to [EK89] Dec] and [DS92] for instance. 3.3 An Abductive Framework for Context Mediation The coinl program resulting from the definition of a domain model, elevation axioms and contexts for the integration of a set of disparate information sources can be equivalently transformed to a normal Horn ....

K. Eshghi and R. Kowalski. Abduction compared with negation as failure. Proc of 6th Intl. Conf. on Logic Programming, 1989.

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K. Eshghi, R.A. Kowalski, Abduction compared with negation as failure. Proc. ICLP'89, MIT Press

....we discuss implementation related issues. 1 Introduction In [3] we have shown that many logics for default reasoning [24, 35, 25, 26] can be understood as special cases of a single abstract framework, based upon an argumentation theoretic interpretation of the semantics of logic programming [12, 13] and its abstractions [9, 10, 4, 21] and extending Theorist [32] In particular, we have shown that the standard (stable) semantics of most logics for default reasoning can be understood as sanctioning a set of assumptions as an extension of a given theory, formulated in some monotonic logic, if ....

....semantics is computationally more feasible than stable semantics. In this paper we de ne two abstract proof procedures for computing admissibility semantics. The second proof procedure is a computationally more ecient re nement of the rst. Both procedures are based upon a proof procedure [13] originally intended for computing stable semantics in logic programming. Although the original proof procedure was proved correct for locally strati ed logic programs, it was shown in [13] to be incorrect for stable semantics in general. Subsequent evaluation of the proof procedure [9, 18, 19] ....

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K. Eshghi, R.A. Kowalski, Abduction compared with negation as failure. Proc. ICLP'89, MIT Press

....to compute (an instance of) a relation implied by the specification. 1 Introduction In [2] we have shown that many default logics [13, 19, 14, 15] can be understood as special cases of a single abstract framework, based upon an abductive interpretation of the semantics of logic programming [7, 8] and its abstractions [4, 5, 1, 11] and extending Theorist [18] Moreover, we have proposed a new semantics for default logics, more liberal than their standard semantics and generalising the admissibility semantics for logic programming [4] equivalent to the partial stable model semantics [20] ....

....to the partial stable model semantics [20] see [10] In this paper, we define two proof procedures for computing the abstract admissibility semantics. The second proof procedure is a computationally more efficient refinement of the first. Both procedures generalise and abstract a proof procedure [8] for logic programming, but are formulated as logic programs. The relationships of the proof procedures with other existing proof procedures for default reasoning and the relevance of the proof procedures in the field of default reasoning are discussed in an extended version of this paper [6] In ....

K. Eshghi, R. A. Kowalski, Abduction compared with negation as failure. Proceedings of the 6th International Conference on Logic Programming, Lisbon, Portugal (1989), MIT Press (G. Levi and M. Martelli, eds) 234--254

....done while the author was a visitor at Imperial College other formalisms for non monotonic reasoning. The new framework was inspired by Dung s general argumentation framework [6] but is formulated differently as a generalisation of the abductive frameworks of Poole [16] and Eshghi and Kowalski [7]. The new framework generalises the approach of [16] and shows how any monotonic logic can be extended to a non monotonic logic by appropriately identifying a set of candidate assumptions and specifying the conditions under which a theory can be extended by an acceptable set of assumptions. It ....

....: l n ; l 1 ; l n p where p 2 HB, l 1 ; l n 2 Lit, and n 0, and of the form p; not p where p 2HB, ffl Ab =HB not . A logic program P is a theory, P L, in such an assumption based framework. The interpretation of negative literals as abducibles was first presented in [7], and was the basis for the preferred extension semantics [4] the stable theory and acceptability semantics [11] and the argumentation theoretic interpretation for the semantics of logic programming presented in [13] The instance of the definition 2.2 of attack for the assumption based ....

K. Eshghi, R. A. Kowalski, Abduction compared with negation as failure. Proc. 6th International Conference on Logic Programming, Lisbon, Portugal, MIT Press (1989)

....show that the proof procedure is complete. 1 Introduction In [3] we have shown that many logics for default reasoning [21, 29, 22, 23] can be understood as special cases of a single abstract framework, based upon an argumentation theoretic interpretation of the semantics of logic programming [11, 12] and its abstractions [8, 9, 4, 18] and extending Theorist [26] In particular, we have shown that the standard (stable) semantics of most logics for default reasoning can be understood as sanctioning a set of assumptions as an extension of a given theory, formulated in some monotonic logic, if ....

....semantics is computationally more feasible than stable semantics. In this paper we define two abstract proof procedures for computing admissibility semantics. The second proof procedure is a computationally more efficient refinement of the first. Both procedures are based upon a proof procedure [12] originally intended for computing stable semantics in logic programming. Although the original proof procedure was proved correct for locally stratified logic programs, it was shown in [12] to be incorrect for stable semantics in general. Subsequent evaluation of the proof procedure [8, 15, 16] ....

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K. Eshghi, R.A. Kowalski, Abduction compared with negation as failure. Proc. ICLP'89, MIT Press

....incomplete information which can be added to programs, provided their addition does not violate the integrity constraints. Various forms of ALP have been presented in the literature (see [8] for a survey) In this paper we present a form of ALP based on those proposed by Eshghi and Kowalski [5, 6] and Kakas and Mancarella [9] We allow both default and non default abducibles, as proposed by Poole [15] Moreover, not only do we use integrity constraints to constrain abducibles, but we also indicate how satisfaction of integrity should be restored. We do this by identifying one or more ....

....is a tuple of terms and X is a tuple of variables. 2 Note that two kinds of negation occur in the integrity constraints, namely : and not. However, neither kind is actually needed. Indeed, negation as failure literals can be replaced by positive abducible atoms and integrity constraints, as in [6]. Moreover, is simply a shorthand indicating that literals are incompatible. expresses the default nature of the persistence axiom and is used to predict information, while the predicate happens is used as a non default abducible to explain observations. If no integrity constraint is violated, ....

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K. Eshghi, R. A. Kowalski, Abduction compared with negation as failure. ICLP'89 (G. Levi and M. Martelli eds.) MIT Press, 234--255

.... A if and only if P 0 [ Delta A. Lemma 7 follows from lemma 8. Here and in the rest of the paper, for any normal logic program Prog, Prog stands for the definite logic program obtained by interpreting every negative literal, not p, in Prog syntactically as a new positive atom, p (see [8]) Similarly, for any set of assumptions Delta, Delta stands for the definite logic program obtained by interpreting every negative literal in Delta as a new positive atom. Lemma 8. For any normal logic program framework hProg; AB; ICi, for any set of assumptions Delta AB and for any ....

K. Eshghi, R.A. Kowalski, Abduction compared with negation as failure. ICLP'89 (G. Levi and M. Martelli eds.) MIT Press, 234--255

....For this reason a number of non monotonic logics [38, 49, 39, 40] have been developed. In this paper, we show that many of these logics can be understood as special cases of a single abstract framework, based upon an argumentation theoretic interpretation of the semantics of logic programming [16, 17] and its abstractions [10, 11, 6, 27] In this framework, a set of assumptions, formulated in an underlying monotonic logic, is regarded as an acceptable extension of a given theory, unless and until there is reason to believe some contrary set of assumptions. Non monotonicity arises because the ....

....ffl R is the set of all inference rules of the form ff fi 1 ; fi n fi 1 ; fi n ff where ff 2 HB and fi 1 ; fi n 2 Lit and n 0; ffl not ff = ff, for each not ff 2 HB not . The interpretation of negative literals as assumptions in logic programming was introduced in [16, 17], and formed the basis for the admissibility semantics [10] the stable theory and acceptability semantics [28] and the argumentation theoretic interpretation for these semantics presented in [25, 11] Note that we could, equivalently, represent clauses ff fi 1 ; fi n as inference ....

[Article contains additional citation context not shown here]

K. Eshghi, R.A. Kowalski, Abduction compared with negation as failure. Proc. ICLP'89, MIT Press

No context found.

Eshghi, Kave, & Kowalski, Robert A. (1989). Abduction compared with negation as failure. Proceedings of the 6th. international conference on logic programming. Lisbon, Portugal: MIT Press.

No context found.

Kave Eshghi and Robert A. Kowalski. Abduction compared with negation as failure. In G. Levi and M. Martelli, editors, Proceedings of the 6th International Conference on Logic Programming, pages 234-254, Lisbon, Portugal, 1989. MIT Press.

No context found.

Eshghi, E. and Kowalski, R., Abduction compared with negation as failure, Proc. of the 6th Int'l Conf. on Logic Programming, G. Levi and M. Martelli eds., MIT Press, 1989, 234-254

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