G. Wagner. Reasoning with inconsistency in extended deductive databases. In L. M. Pereira and A. Nerode, editors, 2nd International Workshop on Logic Programming and Non-monotonic Reasoning, pages 300--315. MIT Press, 1993.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....the answer set semantics of extended disjunctive programs, while they do not treat paraconsistent semantics nor the possible model semantics. Paraconsistent stable model semantics is also proposed by several researchers. Pimentel and Rodi [28] Grant and Subrahmanian [17] and Wagner [36] study paraconsistent stable model semantics from different viewpoints. The differences between these approaches and ours are as follows. First, their paraconsistent stable model semantics are defined for extended logic programs and do not treat disjunctive information in a program. Second, they ....

G. Wagner. Reasoning with inconsistency in extended deductive databases. In Proceedings of the Second International Workshop on Logic Programming and Nonmonotonic Reasoning, MIT Press, pp. 300-315, 1993. 28

....7, 49, 3, 44] The reader is referred to Hunter s Chapter in this volume for a more detailed discussion on the logical properties of several paraconsistent logics. Their intuitions and results have been brought to the logic programming setting mainly by Blair, Pearce, Subrahmanian, and Wagner [8, 39, 40, 36, 37, 59, 60]. The introduction of a non classical explicit form of negation in logic programming led other researchers to address this issue as well, namely Przymusinski, Sakama and ourselves, with respect to extensions of both well founded and answer sets semantics. In this survey we emphasize the ....

....logic programs without default negation (or monotonic extended logic programs) and a semantics which is common denominator to almost all other semantics examined in this survey. It is related to Blair and Subrahmanian s generalized Horn programs [8] Wagner s logic programs with strong negation [59, 60], and Almukdad and Nelson s paraconsistent constructive system N Gamma [3] 3.1 Language and Fixpoint Semantics As usual, for the sake of simplicity and without loss of generality, we will restrict the discussion to (possibly infinite) propositional, or to ground, programs. A non ground ....

[Article contains additional citation context not shown here]

G. Wagner. Reasoning with inconsistency in extended deductive databases. In L. M. Pereira and A. Nerode, editors, LPNMR'93, pages 300--315. MIT Press, 1993.

....WFSX library was implemented by J. Alferes and L.M. Pereira. T. Swift Tabling for Non monotonic Programming 21 logics using tabling. For instance, 16] illustrates how several other logics can be transformed into WFSX these include Generalized Horn Programs [7] Extended Deductive Databases [59], and IMEX Negation [31] and each of these can be evaluated using XSB. In addition meta interpreters have been written in XSB for Head cycle free disjunctive logic programs [6] for Defeasible Logic, using the transformation of [5] for the program update method of [36] and for abduction over ....

G. Wagner. Reasoning with inconsistency in extended deductive databases. In International Workshop on Logic Programming and Non-Monotonic Reasoning, pages 300--315. MIT Press, 1994.

....community [30, 26, 28, 1] It does not necessarily require an explicit paraconsistent semantics: the procedural program transforming revision operators suffice. Paraconsistent approach: Accept contradictory information into the semantics and perform reasoning tasks that take it into account[7, 23, 24, 21, 22, 37, 38, 1]. This is the approach we will further explore in this paper. The first approach only makes sense when dealing with mathematical objects. For instance, if we have a large knowledge base being maintained or updated by different agents, it is natural to encounter inconsistencies in the database. ....

.... reasoning seems to be fundamental for understanding human cognitive processes, it has been studied in philosophical logic by several authors [8, 6, 33, 4, 31] Their intuitions and results have been brought to the logic programming setting mainly by Blair, Pearce, Subrahmanian, and Wagner [7, 23, 24, 21, 22, 37, 38]. The introduction of a non classical explicit form of negation in logic programming led other researchers to address this issue as well, namely Przymusinski, Sakama and ourselves, with respect to extensions of well founded and of answer sets semantics [32, 34, 35, 1, 9] However, with the ....

[Article contains additional citation context not shown here]

G. Wagner. Reasoning with inconsistency in extended deductive databases. In L. M. Pereira and A. Nerode, editors, LPNMR'93, pages 300--315. MIT Press, 1993.

....a :b The above program has fc; bg as the only Omega Gammay 29711 2 The Omega Gammae ell founded semantics is given by ffc; bg; fc; a; bgg. 2 Before we end this section we would like to briefly mention another class of semantics of extended logic programs based on contradiction removal [Dun91b, Wag93, PAA91a, GM90]. To illustrate the problem let us consider the program Pi 4 : 1. p not q 2. p 3. s Obviously, under the answer set semantics this program is inconsistent. It is possible to argue however that inconsistency of Pi 4 can be localized to the rules (1. and (2. and should not influence ....

G. Wagner. Reasoning with inconsistency in extended deductive databases. In Proc. of 2nd International workshop on Logic programming and non-monotonic reasoning, 1993.

.... exchange( B,B) exchange(B, B) ffl Note use of Hilog and Tabling 71 Negation Similar meta interpreters transformations can be performed for ffl Head Cycle Free Disjunctive Logic Programs [10] ffl Generalized Horn Programs [12] ffl Extended Databases [117, 109] ffl Imex Negation [56] ffl A restriction to WFS of the action language A [47] Tabling can also be used as a preprocessor for stable model computations. 72 Negation An Extended Logic Program (C. Damasio) perforation(X) suddenpain(X) abdtenderness(X) peritonealirritation(X) ....

G. Wagner. Reasoning with inconsistency in extended deductive databases. In International Workshop on Logic Programming and Non-Monotonic Reasoning, pages 300--315, 1994.

....community [29, 28, 1] It does not necessarily require an explicit paraconsistent semantics: the procedural program transforming revision operators suffice. Paraconsistent approach: Accept contradictory information into the semantics and perform reasoning tasks that take it into account[6, 25, 26, 23, 24, 38, 39, 1]. This is the approach we will further explore in this paper. The first approach only makes sense when dealing with mathematical objects. For instance, if we have a large knowledge base being maintained or updated by different agents, it is natural to encounter inconsistencies in the database. ....

.... reasoning seems to be fundamental for understanding human cognitive processes, it has been study in philosophical logic by several authors [7, 5, 32, 3, 30] Their intuitions and results have been brought to the logic programming setting mainly by Blair, Pearce, Subrahmanian, and Wagner [6, 25, 26, 23, 24, 38, 39]. The introduction of a non classical explicit form of negation in logic programming led other researchers to address this issue as well, namely Przymusinski, Sakama and ourselves, with respect to extensions of well founded and of answer sets semantics [31, 33, 34, 1, However, with the ....

[Article contains additional citation context not shown here]

G. Wagner. Reasoning with inconsistency in extended deductive databases. In L. M. Pereira and A. Nerode, editors, LPNMR'93, pages 300--315. MIT Press, 1993.

....their negation classical negation 1 . Subsequently, several researchers proposed different, often incompatible, forms of symmetric negation for various semantics of logic programs and deductive databases (Dung Ruamviboonsuk 1991; Pereira Alferes 1992; Przymusinski 1991; 1994b; Pearce 1990; Wagner 1993). To the best of our knowledge, however, no systematic study of symmetric negation in non monotonic reasoning was ever attempted in the past 2 . In this paper we conduct such a systematic study of symmetric negation. ffl We introduce and discuss two natural, yet different, definitions of ....

Wagner, G. 1993. Reasoning with inconsistency in extended deductive databases. In Pereira, L. M., and Nerode, A., eds., 2nd Int. Ws. on LP & NMR, 300-- 315. MIT Press.

....whose precise details are not relevant here, assigns to the above program the meaning (with obvious abbreviations for constants) fman(s) f ly(t) bird(t) not f ly(t)g which corresponds to intuition 3 . 2 Other researchers have defined paraconsistent semantics for contradictory programs [5, 3, 25, 28]. This is not our concern. On the contrary, we wish to remove contradiction whenever it rests on withdrawable assumptions. 3 For the sake of simplicityt, we omit in the model some literals that are irrelevant for the problem (such as f lies(s) f lies(s) bird(s) man(t) etc) All these ....

G. Wagner. Reasoning with inconsistency in extended deductive databases. In L. M. Pereira and A. Nerode, editors, 2nd Int. Ws. on Logic Programming and NonMonotonic Reasoning. MIT Press, 1993. This article was processed using the L a T E X macro package with LLNCS style

....s or if all fix points T of Gamma Gamma s do not comply with T Gamma s T . The next theorem shows that the first case is impossible, i.e. all programs (contradictory or otherwise) have fix points of Gamma Gamma s . 9 This kind of paraconsistent reasoning is called liberal reasoning in [67]. Theorem 5.1 The operator Gamma Gamma s is monotonic, for arbitrary sets of literals. Proof: We have to prove that for arbitrary sets of objective literals A and B: A B ) Gamma Gamma s A Gamma Gamma s B. To do so we begin by proving that both Gamma and Gamma s are anti monotonic: ....

G. Wagner. Reasoning with inconsistency in extended deductive databases. In L. M. Pereira and A. Nerode, editors, 2nd Int. Ws. on LP & NMR, pages 300--315. MIT Press, 1993.

....for logic programs with the stable semantics. Somewhat unfortunately, they called their negation classical negation 1 . Subsequently, several researchers proposed different, often incompatible, forms of symmetric negation for various semantics of logic programs and deductive databases [DR91, PA92, Prz91, Prz94b, Pea90, Wag93]. To the best of our knowledge, however, no systematic study of symmetric negation in non monotonic reasoning was ever attempted in the past 2 . In this paper we conduct such a systematic study of symmetric negation. ffl We introduce and discuss two natural, yet different, definitions of ....

G. Wagner. Reasoning with inconsistency in extended deductive databases. In L. M. Pereira and A. Nerode, editors, 2nd Int. Ws. on LP & NMR, pages 300--315. MIT Press, 1993.

....not a a not a :b The above program has fc; bg as the only Omega#y#29690# 6 The Omega#e ell founded semantics is given by ffc; bg; fc; a; bgg. 2 Before we end this section we would like to briefly mention another class of semantics of extended logic programs based on contradiction removal [Dun91b, Wag93, PAA91a, GM90]. To illustrate the problem let us consider the program 5 4 : 1. p not q 2. p 3. s Obviously, under the answer set semantics this program is inconsistent. It is possible to argue however that inconsistency of 5 4 can be localized to the rules (1. and (2. and should not influence the ....

G. Wagner. Reasoning with inconsistency in extended deductive databases. In Proc. of 2nd International workshop on Logic programming and non-monotonic reasoning, 1993.

....the first case is impossible, i.e. all programs (contradictory or otherwise) have fixpoints of Gamma Gamma s . Theorem 5.1 The operator Gamma Gamma s is monotonic, both for contradictory and non contradictory programs. 7 This kind of paraconsistent reasoning is called liberal reasoning in [72]. Proof: We have to prove that for arbitrary sets of objective literals A and B: A B ) Gamma Gamma s A Gamma Gamma s B. To do so we begin by proving that both Gamma and Gamma s are anti monotonic: Assume that A B. By definition of GL transformation, it is clear that P B P A ....

G. Wagner. Reasoning with inconsistency in extended deductive databases. In L. M. Pereira and A. Nerode, editors, 2nd Int. Ws. on LP & NMR, pages 300--315. MIT Press, 1993.

....reasoning. However their strong negation is different from the strong negation defined in this paper (see Remark 3. 2) Subsequently, several researchers proposed different, often incompatible, forms of symmetric negation for various semantics of logic programs and deductive databases [DR91, PA92, Prz91, Prz95b, Pea90, Wag93]. To the best of our knowledge, however, no systematic study of symmetric negation in non monotonic reasoning was ever attempted in the past 2 . In this paper we conduct such a systematic study of symmetric negation: ffl We introduce and discuss two natural, yet different, definitions of ....

G. Wagner. Reasoning with inconsistency in extended deductive databases. In L. M. Pereira and A. Nerode, editors, 2nd Int. Ws. on LP & NMR, pages 300-- 315. MIT Press, 1993.

No context found.

G. Wagner. Reasoning with inconsistency in extended deductive databases. In L. M. Pereira and A. Nerode, editors, 2nd International Workshop on Logic Programming and Non-monotonic Reasoning, pages 300--315. MIT Press, 1993.

No context found.

G. Wagner. Reasoning with inconsistency in extended deductive databases. In L. M. Pereira and A. Nerode, editors, 2nd International Workshop on Logic Programming and Non-monotonic Reasoning, pages 300--315. MIT Press, 1993.

No context found.

G. Wagner, Reasoning with Inconsistency in Extended Deductive Databases, L.M. Pereira and A. Nerode (eds.), Proc. of the 2nd Intern. Workshop on Logic programming and Non-monotonic Reasoning, 1993, pp.300-315. 32

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G. Wagner, "Reasoning with Inconsistency in Extended Deductive Databases", Proc. of the 2nd Intern. Workshop on Logic Programming and Non-monotonic Reasoning, 1993, pp.300-315. 11

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G. Wagner, "Reasoning with Inconsistency in Extended Deductive Databases ", Proc. of the 2nd Intern. Workshop on Logic programming and Non-monotonic Reasoning, 1993, pp.300-315.

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