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20
Using ModelBased Diagnosis to Build Hypotheses about Spatial Environments
, 2003
"... this paper, we present a solution to the problem how a team of robotic agents can come up with a hypothesis of what might globally be wrong with the environment in similar situations. Hypotheses should entail the currently observed behavior and provide some kind of "forecast" for those are ..."
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Cited by 31 (3 self)
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this paper, we present a solution to the problem how a team of robotic agents can come up with a hypothesis of what might globally be wrong with the environment in similar situations. Hypotheses should entail the currently observed behavior and provide some kind of "forecast" for those areas that no other member of the team visited so far. As time proceeds the hypothesis will be refined to match the actual situation more closely. With a hypothesis about the condition of the environment, single robots can try to avoid areas that potentially contain obstacles, take the shortest way out of these areas, or instead enter these areas to (dis)prove the hypothesis dependent on the strategy of the team
A Deduction Method Complete for Refutation and Finite Satisfiability
 In Proc. 6th European Workshop on Logics in Artificial Intelligence, LNAI
, 1998
"... . Database and Artificial Intelligence applications are briefly discussed and it is argued that they need deduction methods that are not only refutation complete but also complete for finite satisfiability. A novel deduction method is introduced for such applications. Instead of relying on Skolemiza ..."
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Cited by 20 (4 self)
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. Database and Artificial Intelligence applications are briefly discussed and it is argued that they need deduction methods that are not only refutation complete but also complete for finite satisfiability. A novel deduction method is introduced for such applications. Instead of relying on Skolemization, as most refutation methods do, the proposed method processes existential quantifiers in a special manner which makes it complete not only for refutation, but also for finite satisfiability. A main contribution of this paper is the proof of these results. Keywords: Artificial Intelligence, Expert Systems, Databases, Automated Reasoning, Finite Satisfiability. 1 Introduction For many applications of automated reasoning, the tableaux methods [32, 16, 34, 18] have the following advantages: They not only detect unsatisfiability but also generate models; they are close to common sense reasoning, hence easy to enhance with an explanation tool; and they are quite easy to adapt to the special...
Abductive Coreference by Model Construction
 JOURNAL OF LANGUAGE AND COMPUTATION
, 1999
"... In this paper, we argue that the resolution of anaphoric expressions in an utterance is essentially an abductive task following [HSAM93] who use a weighted abduction scheme on horn clauses to deal with reference. We give a semantic representation for utterances containing anaphora that enables us to ..."
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Cited by 16 (2 self)
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In this paper, we argue that the resolution of anaphoric expressions in an utterance is essentially an abductive task following [HSAM93] who use a weighted abduction scheme on horn clauses to deal with reference. We give a semantic representation for utterances containing anaphora that enables us to compute possible antecedents by abductive inference. We extend the disjunctive model construction procedure of hyper tableaux [BFN96, Kuh97] with a clause transformation turning the abductive task into a model generation problem and show the completeness of this transformation with respect to the computation of abuctive explanations. This abductive inference is applied to the resolution of anaphoric expressions in our general model constructing framework for incremental discourse representation [Kuh99] which we argue to be useful for computing information updates from natural language utterances [Vel96].
Capturing Parallel Circumscription with Disjunctive Logic Programs
 SpringerVerlag (2004) 134–146 LNAI 3229
, 2004
"... The stable model semantics of disjunctive logic programs is based on classical models which are minimal with respect to subset inclusion. As a consequence, every atom appearing in a disjunctive program is false by default. This is sometimes undesirable from the knowledge representation point of view ..."
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Cited by 13 (6 self)
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The stable model semantics of disjunctive logic programs is based on classical models which are minimal with respect to subset inclusion. As a consequence, every atom appearing in a disjunctive program is false by default. This is sometimes undesirable from the knowledge representation point of view and a more refined control of minimization is called for. Such features are already present in Lifschitz's parallel circumscription where certain atoms are allowed to vary or to have fixed values while all other atoms are minimized. In this paper, it is formally shown that the expressive power of minimal models is properly increased in the presence of varying atoms. In spite of this, we show how parallel circumscription can be embedded into disjunctive logic programming in a relatively systematic fashion using a linear and faithful, but nonmodular translation. This enables the conscious use of varying atoms in disjunctive logic programs leading to more elegant and concise problem representations in various domains.
Theorem Proving Techniques for View Deletion in Databases
 Journal of Symbolic Computation
, 1999
"... this paper, we show how techniques from firstorder theorem proving can be used for ..."
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Cited by 11 (3 self)
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this paper, we show how techniques from firstorder theorem proving can be used for
A Rational and Efficient Algorithm for View Deletion in Databases
 LOGIC PROGRAMMING  PROCEEDINGS OF THE 1997 INTERNATIONAL SYMPOSIUM, PORT
, 1997
"... In this paper, we show how techniques from disjunctive logic programming and classical firstorder theorem proving can be used for efficient (deductive) database updates. The key idea is to tranform the given database together with the update request into a disjunctive logic program and apply disjun ..."
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Cited by 11 (4 self)
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In this paper, we show how techniques from disjunctive logic programming and classical firstorder theorem proving can be used for efficient (deductive) database updates. The key idea is to tranform the given database together with the update request into a disjunctive logic program and apply disjunctive techniques (such as minimal model reasoning) to solve the original update problem. We present two variants of our algorithm both of which are of polynomial space complexity. One variant, which is based on offline preprocessing, is of polynomial time complexity. We also show that both variants are rational in the sense that they satisfy certain rationality postulates stemming from philosophical works on belief dynamics.
Merge Path Improvements for Minimal Model Hyper Tableaux
 In Proc. TABLEAUX’99
, 1999
"... . We combine techniques originally developed for refutational firstorder theorem proving within the clause tree framework with techniques for minimal model computation developed within the hyper tableau framework. This combination generalizes wellknown tableaux techniques like complement split ..."
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Cited by 9 (0 self)
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. We combine techniques originally developed for refutational firstorder theorem proving within the clause tree framework with techniques for minimal model computation developed within the hyper tableau framework. This combination generalizes wellknown tableaux techniques like complement splitting and foldingup/down. We argue that this combination allows for efficiency improvements over previous, related methods. It is motivated by application to diagnosis tasks; in particular the problem of avoiding redundancies in the diagnoses of electrical circuits with reconvergent fanouts is addressed by the new technique. In the paper we develop as our main contribution in a more general way a sound and complete calculus for propositional circumscriptive reasoning in the presence of minimized and varying predicates. 1 Introduction Recently clause trees [6], a data structure and calculus for automated theorem proving, introduced a general method to close branches based on socalle...
A New Clausal Class Decidable by Hyperresolution
, 2002
"... In this paper we define a new clausal class, called BU, which can be decided by hyperresolution with splitting. We also consider the model generation problem for BU and show that hyperresolution plus splitting can also be used as a Herbrand model generation procedure for BU and, furthermore, that ..."
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Cited by 9 (4 self)
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In this paper we define a new clausal class, called BU, which can be decided by hyperresolution with splitting. We also consider the model generation problem for BU and show that hyperresolution plus splitting can also be used as a Herbrand model generation procedure for BU and, furthermore, that the addition of a local minimality test allows us to generate only minimal Herbrand models for clause sets in BU. In addition, we investigate the relationship of BU to other solvable classes.
Computational Space Efficiency and Minimal Model Generation for Guarded Formulae
, 2001
"... This paper describes two hyperresolutionbased decision procedures for a subfragment of the guarded fragment. The rst procedure is a polynomial space decision procedure which eectively corresponds to polynomial space tableauxbased algorithms without blocking. The second procedure is a minimal mo ..."
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Cited by 7 (6 self)
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This paper describes two hyperresolutionbased decision procedures for a subfragment of the guarded fragment. The rst procedure is a polynomial space decision procedure which eectively corresponds to polynomial space tableauxbased algorithms without blocking. The second procedure is a minimal model generation procedure which constructs all and only minimal Herbrand models for guarded formulae. This procedure is based on hyperresolution, complement splitting and a model constraint propagation rule. Both procedures have concrete application domains and are relevant for all multimodal and description logics that can be embedded into the guarded fragment.
Hierarchical Diagnosis of Large Configurator Knowledge Bases
, 2001
"... Debugging, validation, and maintenance of configurator knowledgebases are important tasks for the successful deployment of product configuration systems. Consistencybased diagnosis has shown to be a promising approach for detecting faulty parts in the knowledge bases and explaining unexpected behav ..."
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Cited by 4 (3 self)
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Debugging, validation, and maintenance of configurator knowledgebases are important tasks for the successful deployment of product configuration systems. Consistencybased diagnosis has shown to be a promising approach for detecting faulty parts in the knowledge bases and explaining unexpected behavior of the configurator, whereby (partial) configurations are used as test cases. In this paper,