J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Special Issue of the Journal of Automated Reasoning, 14(1):93--147, 1995.  Home/Search   Document Details and Download   Summary   Related Articles   Check

.... been found equivalent to the well founded semantics for extended logic programs, WFSX [16, 2] This paper makes the following contributions: we de ne a least xpoint argumentation semantics for extended logic programs, and show its equivalence to the well founded semantics with explicit negation [16, 2, 1]. In order to relate this semantics to other argumentation semantics, we set up a general framework to classify notions of justi ed arguments, and use it to compare our argumentation semantics to those of Dung [6] and Prakken and Sartor [17] among others. We develop a general dialectical proof ....

....di er, and both di er from u=a justi ability, which will be shown equivalent to the well founded semantics WFSX [16, 2] in the following section. 4 Well founded semantics We recollect the de nition of the well founded semantics for extended logic programs, WFSX. We use the de nition of [1], because it is closer to our de nition of argumentation semantics than the original de nition of [16, 2] De nition 8 The set of all objective literals of a program P is called the Herbrand base of P and denoted by H(P ) A pseudo interpretation of a program P is a set T [ not F where T and ....

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J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Journal of Automated Reasoning, 14(1):93-147, 1995.

....11 Let P be an extended logic program and WFM(P ) its well founded model [2] Then WFM(P ) L there exists a u a justified argument for L # not all arguments for L are attacked by a u a justified argument . Proof (Sketch) For the sake of brevity we can only sketch the proof. In [1], the well founded model is defined as the least fixpoint of the operator ##s , where # is the Gelfond Lifschitz operator [9] and #s is the same operator applied to the semi normal version of the program, obtained by adding not to the body of each rule with head L. The fixpoint is generated by ....

....logic programs [2] The results concerning the relationships as depicted in Fig. 3 have been valuable in identifying such a semantics, as well as relating it to existing semantics. Furthermore the equivalence of J u a and WFSX allow the use of the efficient top down proof procedure for WFSX [1] to compute justified arguments in J u a . Future research will determine how to adapt this proof procedure to different argumentation semantics and its relation to dialogue games as defined in [7, 13, 16, 11] It is also an open question how the hierarchy changes when priorities are added as ....

J. J. Alferes, C. V. Dam asio, and L. M. Pereira, `A logic programming system for non-monotonic reasoning', Journal of Automated Reasoning, 14(1), 93--147, (1995).

....Trying to prove p in P 1 Prolog applies the rule p p over and over again. A similar reason stops P 2 from terminating in Prolog. The problems occur in general due to positive or negative loops through recursion. To deal with this problem we de ne T and TU trees, to prove verity and non falsity [ADP94a, ADP94b, ADP95, AP96]. De nition 8 Fuzzy T tree, TU tree Let P be a ground fuzzy extended logic program, let true be a new unary predicate symbol, and let P 0 be the program obtained from P by replacing rules of the form L with L true(1) and rules of the form L : V with L true(V ) A fuzzy T tree (resp. ....

J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Journal of Automated Reasoning, 14(1):93-147, 1995.

....of G, a new rule G # # not G is introduced with a new atom G # . Then, an antiexplanation of G can be obtained as a credulous explanation of G # . 6 On the other hand, negative or mixed (anti )explanations cannot be directly computed by other abductive procedures. Alferes, Damasio and Pereira [2,10] propose an abductive framework within the three valued semantics in a di#erent way. Abduction is performed in their revision system to remove a contradiction in a program by changing the truthvalue of abducible literals into true, false or undefined, in which the change from true to ....

....value of an abducible is due to their three valued semantics, which very roughly corresponds to the situation that true is assigned to the abducible in some stable model and false is also assigned to it in another stable model. Their abductive framework is computed using their top down procedure [2], but they do not produce a transaction program. Usually, top down procedures like [23,10 12] compute one explanation at a time, but the minimality of an abductive explanation is not guaranteed in general. Our fixpoint operator in Definition 3.3, on the other hand, involves computation of all ....

J. J. Alferes, C. V. Damasio and L. M. Pereira, A logic programming system for nonmonotonic reasoning, J. Automated Reasoning, 14 (1995) 93--147.

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J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Special Issue of the Journal of Automated Reasoning, 14(1):93--147, 1995.

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J. J. Alferes, C. V. Dam asio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Special Issue of the Journal of Automated Reasoning, 14(1):93--147, 1995.

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J. J. Alferes, C. V. Dam'asio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Special Issue of the JAR, 1995. To appear.

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J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Special Issue of the Journal of Automated Reasoning, 14(1):93--147, 1995.

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Alferes, J. A., C. Damasio and L. M. Pereira. 1995. "A logic programming system for non-monotonic reasoning", Journal of Automated Reasoning 14: 93-147.

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J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Special Issue of the Journal of Automated Reasoning, 14(1):93-147, 1995.

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Alferes, J. A., C. Damasio and L. M. Pereira. 1995. "A logic programming system for non-monotonic reasoning," Journal of Automated Reasoning 14: 93-147.

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J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Special Issue of the Journal of Automated Reasoning, 14(1):93--147, 1995.

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J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. J. of Automated Reasoning, 14(1):93--147, 1995.

....denote the formula , where A 1 . Am and B 1 ; Bn are, respectively, the isotonic and antitonic occurrences, of propositional symbols in in the order they appear in (left to right) Regarding the semantics, we follow a paraconsistent and paracomplete approach inspired by WFSX p [3, 6], one of the well founded based semantics proposed for extended logic programs. A technique used in logic programming literature resorts to the notion of partial interpretation, requiring rst the usual notion of interpretation. De nition 8 (Interpretation) Consider a bilattice B = hB; t ; ....

.... M i of P complies with the Coherence Principle i for every propositional symbol A appearing in the language of P , d M (A) k d M ( A) Given these arguments, and in order to enforce coherence, we will resort to the semi normal gamma operator, inspired by the approach taken in [3, 6]: De nition 15 (Semi normal Gamma operator) Let P be a paraconsistent logic program and J an interpretation. The semi normal immediate consequences operator T I ; J ( k A) j A 2 P We also de ne (J) lfp T Mark that coherence is enforced in every propositional ....

J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Special Issue of the Journal of Automated Reasoning, 14(1):93-147, 1995.

....turned out to be a promising approach to cope with negation by default. Subsequent work extended well founded semantics with a form of explicit negation and constraints [19] and showed that the richer language, called WFSX, is appropriate for a spate of knowledge representation and reasoning forms [2, 5]. In particular, the technique of contradiction removal of extended logic programs [20] opens up many avenues in model based diagnosis [5, 24] Definition 1. Extended Logic Program An extended logic program is a (possibly infinite) set of rules of the form L 0 L 1 ; Lm ; notLm 1 ; ....

J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for nonmonotonic reasoning. Journal of Automated Reasoning, 14(1):93--147, 1995.

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) J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Journal of Automated Reasoning, 14:93-147, 1995.

....the application of a contradiction removal process based on revising assumptions, possibly adopting of some other assumptions instead. This too has been extensively studied in AI and in the LP setting, and as a result automated reasoning systems have been made available which do that work for us [1]. 5.10 Updating Last but not least, work in LP has concerned itself with the updating of a knowledge base by another one. This notion of knowledge updating, as opposed to that of simple fact updating, opens up another dimension to the dynamics of logic, in contradistinction to the statics of the ....

J.Alferes, C.Damasio, L.Pereira, "A logic programming system for non-monotonic reasoning". J. Automated Reasoning, 14:93-147, 1995.

.... all extensions of a state of the art diagnoser, such as preferences and strategies [FNS94,NFS95] can be incorporated into the existing approach [DNPS95] The more recent second implementation of REVISE is based on a new top down evaluation of well founded semantics with explicit negation (WFSX) [ADP94a,ADP94b,ADP95], which lead to a dramatic speed increase. The REVISE system is embedded into an architecture for a diagnosis agent consisting of three layers: a knowledge base, an inference layer, and on top a component for communication and control (see Fig. 1) The core of the inference machine is the REVISE ....

....out to be a promising approach to cope with negation by default. Subsequent work extended well founded semantics with a form of explicit negation and constraints [PA92] and showed that the richer language, called WFSX, is appropriate for a spate of knowledge representation and reasoning forms [PAA93,PDA93,ADP95]. In particular, the technique of contradiction removal from extended logic programs [PAA91] opens up many avenues in model based diagnosis [PDA93,DNP94,DNPS95,MA95] Definition 1. Extended Logic Program An extended logic program is a (possibly infinite) set of rules of the form L 0 L 1 ; ....

[Article contains additional citation context not shown here]

J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Journal of Automated Reasoning, 14(1):93--147, 1995.

....[8] turned out to be a promising approach to cope with negation by default. Subsequent work extended well founded semantics with a form of explicit negation [11, 4] defining WFSX , and showed that the richer language is appropriate for a spate of knowledge representation and reasoning forms [9, 10, 3]. Definition 2.1 An extended logic program is a (possibly infinite) set of ground rules of the form L 0 L 1 ; L l ; not L l 1 ; not Lm (0 l m) where each L i is an objective literal (0 i m) If n = 0 then the rule is called a fact and the arrow symbol is ommited. An ....

....we review WFSX [4] a semantics for extended logic programs. For similarity with Prakkens s argumentation, instead of the declarative (bottom up) original definition of WFSX , we present an equivalent top down inference operator for WFSX . The equivalence between the definitions is shown in [3]. The inference operator has three parameters M , LA, and GA, where M is either t or tu indicating that we want to prove verity (t) and non falsity (tu) and LA and GA are lists of local and global ancestors that allow to detect negative and positive loops which lead to inference of non falsity ....

[Article contains additional citation context not shown here]

J. J. Alferes, C. V. Dam'asio, and L. M. Pereira. A logic programming system for nonmonotonic reasoning. Journal of Automated Reasoning, 14(1):93--147, 1995.

....addressed [14, 23, 24] Program updating is distinct from program revision, where a program accommodates, perhaps non monotonically by revising assumptions, additional information about a world state. Work on logic programs revision (or contradiction removal) has received more attention (e.g. in [3, 5, 22, 40, 41]) A key insight into the issue of updating theories is due to Winslett [39] who showed that, contrary to theory revision, one must consider the e ect of an update in each of the states of the world that are consistent with our current knowledge of its state. The following realistic situation ....

J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Journal of Automated Reasoning, 14:93-147, 1995.

....satisfied constraints, thus improving the fitness, as required by the notion of Lamarckian operator. To find support sets we need to know which literals belong to the model of a program. This information is obtainable through some sound and correct procedure for WFSXp such as the one described in [ADP95], or the one in [APS99] In the case of the circuit diagnosis problems in section 4, the support sets procedure becomes simplified in that the occurrences of default negated literals pertain only to revisables. When computing the support sets, the Lamarckian operator also modifies an extra bit ....

J. J. Alferes, C. V. Dam'asio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Journal of Automated Reasoning, 14:93--147, 1995.

....out to be a promising approach to cope with negation by default. Subsequent work extended well founded semantics with a form of explicit negation and constraints [11,4] and showed that the richer language, called WFSX, is appropriate for a spate of knowledge representation and reasoning forms [9,10,3]. Definition 1. Extended Logic Program, Integrity Constraint An extended logic program is a (possibly infinite) set of rules of the form L 0 L 1 ; L l ; not L l 1 ; not Lm (0 l m) where each L i is an objective literal (0 i m) An objective literal is either an atom A or its ....

J. J. Alferes, C. V. Damasio, and L. M. Pereira. A logic programming system for nonmonotonic reasoning. Journal of Automated Reasoning, 14(1):93--147, 1995.

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Jos'e J'ulio Alferes, Carlos Dam'asio, and Lu'is Moniz Pereira. A logic programming system for nonmonotonic reasoning. Journal of Automated Reasoning, 14:93--147, 1995.

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J. Alferes, C. Damasio, and L. M. Pereira. A logic programming system for nonmonotonic reasoning. Journal of Automated Reasoning, 14(1):93-147, 1995.

No context found.

J. J. Alferes, C. V. Dam'asio, and L. M. Pereira. A logic programming system for non-monotonic reasoning. Journal of Automated Reasoning, 14(1):93--147, Feb. 1995.

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