P. Cholewi nski, V.W. Marek, A. Mikitiuk, and M. Truszczy nski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, pages 267--281, Tokyo, June 1995.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....of different design decisions on the performance. Families of similar test cases with increasing complexity are also important for evaluating the scalability of the implementation and for determining the limits of its performance. Our system can be seen as an extension of the TheoryBase system [30] which generates test default theories and normal logic programs using the same idea of creating test cases from graph problems. For generating graphs, TheoryBase uses Knuth s Stanford GraphBase [55] which is a portable collection of programs and data that serves as a platform for combinatorial ....

P. Cholewi nski, V.W. Marek, A. Mikitiuk, and M. Truszczy nski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, pages 267--281, Tokyo, June 1995.

....21 Needless to say, we do not claim that the static semantics should replace the disjunctive stable semantics. Like it is the case with normal logic programs, there are some application domains for which the disjunctive stable semantics seems to be better suited to represent their intended meaning [Cholewi nski et al. 1995]. However, we do claim that the static semantics is the most natural and well behaved extension of the well founded semantics to disjunctive programs and beyond. Because of the importance of the well founded semantics for normal programs, it is of great importance to find the its proper ....

Cholewi' nski, P., Marek, V., Mikitiuk, A., and Truszczy' nski, M. 1995. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming (Tokyo, June 1995), pp. 267--281.

....for P 2 or P 2 can be polynomially transformed into an equivalent reasoning task in any of the classical nonmonotonic formalisms such as default logic, autoepistemic logic, circumscription, etc. Thus, theorem provers for such formalisms, e.g. the DeReS system for default logic (cf. [13]) can be fruitfully used for performing default abduction as well. Such polynomial transformations can be extracted from the proofs of the complexity results, by simply composing transformations. In many cases, however, a direct and much simpler transformation can be found. In fact, we show below ....

....of complexity, can not be substantially improved with concern of solving the problem on all instances. For example, consider the straightforward algorithm in Table 2. There, it is assumed that a procedure skept inf(W; D; for skeptical inference of from hW; Di is available (cf. the DeReS system [13]) and is any contradiction. This algorithm is exponential, even if skept inf is seen as an zero cost oracle; the complexity result for this problem ( P 4 completeness, which loosely speaking means P 2 completeness modulo skeptical inference) however, indicates that there is basically ....

[Article contains additional citation context not shown here]

P. Cholewinski, W. Marek, A. Mikitiuk, and M. Truszczynski. Experimenting with Nonmonotonic Reasoning. In Proc. ICLP-95, Shonan Village Center, Japan, June 1995. MIT-Press.

....problems in NP can be expressed in a very simple and natural way by HCF programs [20, 7, 8] a number of rules with HCF disjunction may guess the solution which is then checked by disjunction free rules. For instance, all problems suggested as benchmarks for nonmonotonic reasoning systems in [12] are naturally expressed by HCF programs. With every program P, we associate a directed graph DGP = N ; E) called the dependency graph of P, in which (i) each predicate of P is a node in N and (ii) there is an arc in E directed from a node a to a node b iff there is a rule r in P such that b ....

....Disjunctive Deductive Databases, where a disjunctive deductive database system based on the techniques presented here is actually implemented and tested. The testing of the system will follow the methodology for experimenting with nonmonotonic reasoning systems developed by Cholewi nski et al. [12]. Another question that we are investigating actively is whether, besides elegantly characterizing the stable model semantics, our new definition of unfounded sets permits definition of a suitable extension of the well founded semantics to disjunctive logic programs. 37 Acknowledgments The ....

Cholewi'nski, P., Marek, V.W., Mikitiuk A. and Truszczy'nski, M. (1995), Experimenting with Nonmonotonic Reasoning, in "Proc. of the 12th International Conference on Logic Programming," pp.267--281, MIT Press.

....technology and programming environments for nonmonotonic reasoning. Combined with an integrated support for various mechanisms of nonmonotonic reasoning, the resulting system offers a more realistic testbed for applications of common sense reasoning. A Programs for Several Graph Problems In [8], a family of encodings of graph problems is proposed for experimental studies of nonmonotonic reasoning. This appendix includes programs with tabled predicates for the graph problems from [8] The use of universal rules, of the form H L 1 ; L n where H is an atom and each L i (1 i n; n ....

....realistic testbed for applications of common sense reasoning. A Programs for Several Graph Problems In [8] a family of encodings of graph problems is proposed for experimental studies of nonmonotonic reasoning. This appendix includes programs with tabled predicates for the graph problems from [8]. The use of universal rules, of the form H L 1 ; L n where H is an atom and each L i (1 i n; n 0) is a literal, allows a more convenient specification. In the following, a unary predicate vertex and a binary predicate arc are used for the representation of a directed graph. A.1 ....

P. Cholewi'nski, V.W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Intl. Conference on Logic Programming. MIT Press, Cambridge, MA, 1995. 14

....what is expressible in each formalism. 4.2.1 Expressing Hard Graph Problems The authors of the paper about DeReS describe their implementation, which is based on theorem provers, and present some experimental results of their system when applied to problems generated by TheoryBase. TheoryBase [3] takes instances of graph problems, such as COLORABILITY, HAMILTON CIRCUIT or KERNELS, and generates default theories, the extensions of which are solutions to the problems. The graphs are generated using the Stanford Graph Base [9] Although TheoryBase is intended to be used as a testbed for ....

P. Cholewi'nski, V. W. Marek and M. Truszczy'nski. Experimenting with Nonmonotonic Reasoning. Proceedings of the 12th International Conference on Logic Programming, 1995.

....constraints without extending the language to allow constraint expressions in the rules. Recently, similar ideas on employing rules as a methodology for expressing constraints capturing many kinds of problems such as combinatorial problems, graph problems and diagnosis, have been presented [9, 10, 14, 4, 5]. Especially close to our approach is the proposal put forward independently by Marek and Truszczy nski [25] to use stable models as an alternative basis for logic programming where rules are interpreted as constraints in the same way as in our approach. The novel constraint programming paradigm ....

P. Cholewinski, V.W. Marek, A. Mikitiuk, and M. Truszczynski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, pages 267-281, Tokyo, June 1995.

....kinds of hard instances can be solved provided that adequate amount of running time is allocated. We have tested the implementation extensively. In order to obtain challenging test cases we have used, e.g. combinatorial graph problems as a test domain. This domain has also been used in TheoryBase [5] which is a system for generating test cases for nonmonotonic reasoning. There are several approaches to computing stable models (see, e.g. 1] Recently, some more advanced implementations have emerged [2, 4, 14, 6] The methods described in [2, 14] cannot handle programs with a large number of ....

P. Cholewi#ski, V.W. Marek, A. Mikitiuk, and M. Truszczy#ski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, pages 267281, Tokyo, June 1995.

....of different design decisions on the performance. Families of similar test cases with increasing complexity are also important for evaluating the scalability of the implementation and for determining the limits of its performance. Our system can be seen as an extension of the TheoryBase system [CMMT95] which generates test default theories and normal logic programs using the same idea of creating test cases from graph problems. For generating graphs, TheoryBase uses Knuth s Stanford GraphBase [Knu93] which is a portable collection of programs and data that serves as a platform for ....

P. Cholewi'nski, V.W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, pages 267--281, Tokyo, June 1995.

....to the original program under a wide range of semantics. For instance, our transformation preserves stable models. So it can also be used as a preprocessing step for algorithms computing stable models [18] e.g. 1] Interesting applications of stable models have recently been studied in [13, 22]. The rest of the paper is organized as follows. After introducing preliminaries in Section 2, we recall the alternating fixpoint procedure in Section 3. The transformation framework that our method is based on is introduced in Section 4 and an immediate consequence operator appropriate for this ....

P. Cholewi'nski, V. W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In L. Sterling, editor, Logic Programming, Proc. of the Twelfth Int. Conf. on Logic Programming (ICLP'95), pages 267--281. MIT Press, 1995.

....solve these kinds of hard instances provided that adequate amount of running time is allocated. We have tested the implementation extensively. In order to obtain challenging test cases we have used, e.g. combinatorial graph problems as a test domain. This domain has also been used in TheoryBase [5] which is a system for generating test cases for nonmonotonic reasoning. There exist several approaches to computing stable models (see, e.g. 1] Our method compares favorably with recent implementations [2, 4, 11] The methods described in [2, 11] cannot handle programs with a large number of ....

P. Cholewi'nski et al. Experimenting with nonmonotonic reasoning. In Proc. of the 12th International Conference on Logic Programming, pp. 267--281, Tokyo, June 1995.

....to the original program under a wide range of semantics. For instance, our transformation preserves stable models. So it can also be used as a preprocessing step for algorithms computing stable models, e.g. BNNS93] Interesting applications of stable models have recently been studied in [SZ95, CMMT95]. In the context of deductive databases it is customary to have a very simple ( naive ) bottom up procedure, which is later made goal directed by means of a (suitable form of) magic set transformation. This separation of issues makes the approach easier to understand and simplifies the correctness ....

Pawe/l Cholewi'nski, V. Wiktor Marek, Artur Mikitiuk, and Miros/law Truszczy'nski. Experimenting with nonmonotonic reasoning. In Leon Sterling, editor, Logic Programming, Proc. of the Twelfth Int. Conf. on Logic Programming (ICLP'95), pages 267--281. MIT Press, 1995.

....solve these kinds of hard instances provided that adequate amount of running time is allocated. We have tested the implementation extensively. In order to obtain challenging test cases we have used, e.g. combinatorial graph problems as a test domain. This domain has also been used in TheoryBase [CMMT95] which is a system for generating test cases for nonmonotonic reasoning and logic programs. Our implementation compares favorably with other existing implementations of the stable model semantics [BNNS94, CW94, SNV94] The methods described in [BNNS94, SNV94] do not seem to be able to handle ....

P. Cholewi'nski, V.W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, Tokyo, June 1995.

....not have yet significant benchmarks of the system. However, we plan to evaluate the performances of our system by a meaningful and thorough experimentation. The testing of the system will follow the methodology for experimenting with nonmonotonic reasoning systems developed by Cholewi nski et al. [7]. We will compare our system mainly to other disjunctive deductive database systems but we will also contrast the performances of our system to the current state of the art implementations of the stable model semantics for normal programs (like, e.g. 6, 20, 28] in order to determine how much ....

P. Cholewi'nski, V.W. Marek, A. Mikitiuk, M. Truszczy'nski. Experimenting with Nonmonotonic Reasoning, In Proc. ICLP '95, pp.267--281, MIT Press, 1995.

....been rather ad hoc. More comprehensive experimental studies are needed that will give insights into the computational nature of stable models and will lead to faster algorithms. To support such studies one needs benchmarking systems. One step in this direction is TheoryBase, a system described in [CMMT95,CMMT98] Next, the SLP seems to be especially well suited for dealing with constraint satisfaction problems. Thus, it is important to extend the language of the SLP so that important classes of constraints involving arithmetic operations and relations became easier to model. Possibility of ....

P. Cholewinski, W. Marek, A. Mikitiuk, and M. Truszczynski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, pages 267-281. MIT Press, 1995.

....T I to P ) Then, answer sets to T I (P ) must be computed and shifted back by means of T I . To compute the answer sets of the general logic program T I (P ) one might use any of the existing systems computing stable models of logic programs (for instance s models [NS96] DeReS [CMMT95] and for disjunctive case DisLoP [ADN97] or a system dlv presented in [ELM 97] Some care needs to be taken to model rules with negation as failure operator in the heads as standard logic program clauses or defaults. In our future work, we will investigate the efficiency of this approach ....

P. Cholewi'nski, W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Logic programming (Kanagawa, 1995), MIT Press Series in Logic Programming, pages 267--281, Cambridge, MA, 1995. MIT Press.

....smodels [NS95] FROST [EFK 95] However, one of the main problems in the efforts to develop reasoning systems based on nonmonotonic logic is the lack of adequate experimentation testbed. This issue was discussed and several encodings which can serve as benchmark problems were presented in [CMMT95b] Also, a software system TheoryBase to automatically generate test logic programs and default theories was developed and is publicly available [CMMT95b] TheoryBase is is an extension of the Stanford GraphBase [Knu93] For any graph from the Stanford GraphBase it can generate encodings for such ....

....lack of adequate experimentation testbed. This issue was discussed and several encodings which can serve as benchmark problems were presented in [CMMT95b] Also, a software system TheoryBase to automatically generate test logic programs and default theories was developed and is publicly available [CMMT95b] TheoryBase is is an extension of the Stanford GraphBase [Knu93] For any graph from the Stanford GraphBase it can generate encodings for such problems as as coloring, hamiltonicity, existence of kernels (see [CMMT95a] for details) 1 . However, TheoryBase supports only a fixed amount of ....

[Article contains additional citation context not shown here]

P. Cholewi'nski, W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, Cambridge, MA, 1995. MIT Press.

....called the TheoryBase, that generates families of default theories for use in experimental studies. We describe results of experiments with DeReS that used as test cases default theories generated by the TheoryBase. This paper is a full version of the material presented in two extended abstracts: CMMT95] and [CMT96] y Corresponding author. 1 The area of nonmonotonic logics originated in the late 1970s [Rei78, Rei80, MD80, McC80] in an effort to build effective knowledge representation formalisms. Since then, solid theoretical foundations of nonmonotonic logics have been established. The ....

P. Cholewi'nski, W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, pages 267--281. MIT Press, 1995. 34

....(DeReS [6] smodels [16] FROST [10] However, one of the main problems in the efforts to develop reasoning systems based on nonmonotonic logic is the lack of adequate experimentation testbed. This issue was discussed and several encodings which can serve as benchmark problems were presented in [7]. Also, a software system TheoryBase to automatically generate test logic programs and default theories was developed and is publicly available [7] TheoryBase is is an extension of the Stanford GraphBase [12] For any graph from the Stanford GraphBase it can generate encodings for such problems ....

....is the lack of adequate experimentation testbed. This issue was discussed and several encodings which can serve as benchmark problems were presented in [7] Also, a software system TheoryBase to automatically generate test logic programs and default theories was developed and is publicly available [7]. TheoryBase is is an extension of the Stanford GraphBase [12] For any graph from the Stanford GraphBase it can generate encodings for such problems as as coloring, hamiltonicity, existence of kernels (see [6] for details) 1 . However, TheoryBase supports only a fixed amount of propositional ....

[Article contains additional citation context not shown here]

P. Cholewi'nski, W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, Cambridge, MA, 1995. MIT Press.

....been rather ad hoc. More comprehensive experimental studies are needed that will give insights into the computational nature of stable models and will lead to faster algorithms. To support such studies one needs benchmarking systems. One step in this direction is TheoryBase, a system described in [CMMT95, CMMT98] Next, the SLP seems to be especially well suited for dealing with constraint satisfaction problems. Thus, it is important to extend the language of the SLP so that important classes of constraints involving arithmetic operations and relations became easier to model. Possibility of ....

P. Cholewi'nski, W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, pages 267--281. MIT Press, 1995.

.... generalization used in these notes, that guarantees neither existence nor uniqueness of stable models but can be viewed as a divide andconquer approach to stable model computation, was developed in [Cho95b, Cho95a] The material of Section 14 extends the approach and the results presented in [CMMT95, CMT96]. It is based on our development work which resulted in two software systems: TheoryBase and DeReS. TheoryBase is a system to automatically generate test cases (in our case, default theories and logic programs) for experimentation. DeReS is an automated reasoning system based on default logic. It ....

P. Cholewi'nski, W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, Cambridge, MA, 1995. MIT Press.

....namely the family of all extensions of Delta, ext( Delta) Hence, default theories can be viewed as encodings of families of subsets of some universe described by a propositional language. Examples of encodings describing families of colorings, kernels, and hamilton cycles in graphs are given in [CMMT95]. 1 Department of Computer Science, University of Kentucky, Lexington, KY 40506 0046, USA. E mail: marek cs.engr.uky.edu, Fax: 606) 323 1971. 2 Free University Amsterdam, Department of Mathematics and Computer Science, Artificial Intelligence Group, De Boelelaan 1081a, 1081 HV Amsterdam, ....

P. Cholewi'nski, W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, Cambridge, MA, 1995. MIT Press.

....real application domains. The problem has been recognized for quite some time. But now we do not have any excuses to avoid it any more. When we develop implementations, why are we doing this Who, in our expectations, will be using these systems and for what purpose 2 TheoryBase is described in [CMMT95]. It can be obtained by anonymous ftp from al.cs.engr.uky.edu by retrieving file TheoryBase.tar.gz from the directory cs software logic. In what applications the technology we are developing has a chance to become commonly accepted and used I will not offer any answers to these questions. But ....

P. Cholewi'nski, W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Proceedings of the ICLP-95, MIT Press, 1995,

No context found.

Pawe/l Cholewi'nski, V. Wiktor Marek, Artur Mikitiuk, and Miros/law Truszczy'nski. Experimenting with nonmonotonic reasoning. In Leon Sterling, editor, Logic Programming, Proc. of the Twelfth Int. Conf. on Logic Programming (ICLP'95), pages 267--281. MIT Press, 1995.

No context found.

P. Cholewi'nski, V.W. Marek, A. Mikitiuk, and M. Truszczy'nski. Experimenting with nonmonotonic reasoning. In Proceedings of the 12th International Conference on Logic Programming, pages 267--281, Tokyo, June 1995.

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