In previous papers, we have presented a logic-based framework for merging structured news reports. Structured news reports are XML documents, where the text entries are restricted to individual words or simple phrases...
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In previous papers, we have presented a logic-based framework for merging structured news reports. Structured news reports are XML documents, where the text entries are restricted to individual words or simple phrases, such as names and domain-specific terminology, and numbers and units. We assume structured news reports do not require natural language processing. In this paper, we present prepositional fusion rules as a way of implementing logic-based fusion for structured news reports. Fusion rules are a form of scripting language that define how structured news reports should be merged. The antecedent of a fusion rule is a call to investigate the information in the structured news reports and the background knowledge, and the consequent of a fusion rule is a formula specifying an action to be undertaken to form a merged report. It is expected that a set of fusion rules is defined for any given application. We give the syntax and mode of execution for fusion rules, and explain how the resulting actions give a merged report.
Induction of the effects of actions considered here consists in learning an action description of a dynamic system from evidence on its behavior. General logic-based induction methods can deal with this problem but, u...
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ISBN:
(纸本)9783540399179
Induction of the effects of actions considered here consists in learning an action description of a dynamic system from evidence on its behavior. General logic-based induction methods can deal with this problem but, unfortunately, most of the solutions provided have the frame problem. To cope with the frame problem induction under suitable nonmonotonic formalisms has to be used, though this kind of induction is not well understood yet. We propose an alternative method that relies on the identification of a monotonic induction problem whose solutions correspond one-to-one to those of the original problem without the frame problem. From this result induction of the effects of actions can be characterized under current monotonic induction methods.
Default logic is one of the best known and most studied of the approaches to nonmonotonic reasoning. Subsequently, several variants of default logic have been proposed to give systems with properties differing from th...
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ISBN:
(纸本)3540404945
Default logic is one of the best known and most studied of the approaches to nonmonotonic reasoning. Subsequently, several variants of default logic have been proposed to give systems with properties differing from the original. In this paper we show that these variants are in a sense superfluous, in that for any of these variants of default logic, we can exactly mimic the behaviour of a variant in standard default logic. We accomplish this by translating a default theory under a variant interpretation into a second default theory wherein the variant interpretation is respected.
We investigate rule dependency graphs and their colorings for characterizing the computation of answer sets of logic programs. We start from a characterization ofanswer sets in terms oftotally colored dependency graph...
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We investigate rule dependency graphs and their colorings for characterizing the computation of answer sets of logic programs. We start from a characterization ofanswer sets in terms oftotally colored dependency graphs. To a turn, we develop a series ofoperational characterizations ofanswer sets in terms ofoperators on partial colorings. In analogy to the notion ofa derivation in proof theory, our operational characterizations are expressed as (non-deterministically formed) sequences ofcolorings, turning an uncolored graph into a totally colored one. This results in an operational framework in which different combinations ofoperators result in different formal properties. Among others, we identify the basic strategy employed by the noMoRe system and justify its algorithmic approach. Also, we distinguish Fitting's and well-founded semantics.
Strategy annotations are used in eager programming languages (e.g., OBJ2, OBJ3, CafeOBJ, and Maude) for improving efficiency and/or reducing the risk of nontermination. Syntactically, they are given either as lists of...
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Several earlier papers have shown that bounded quantification is an expressive and comfortable addition to logic programming languages. One shortcoming of bounded quantification, however, is that it does not allow eas...
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ISBN:
(纸本)3540003894
Several earlier papers have shown that bounded quantification is an expressive and comfortable addition to logic programming languages. One shortcoming of bounded quantification, however, is that it does not allow easy and efficient relation of corresponding elements of aggregations being quantified over (lockstep iteration). Bounded quantification also does not allow easy quantification over part of an aggregation, nor does it make it easy to accumulate a result over an aggregation. We generalize the concept of bounded quantification to quantification over any finite sequence, as we can use a rich family of operations on sequences to create a language facility that avoids the weaknesses mentioned above. We also propose a concrete syntax for sequence quantification in Prolog programs, which we have implemented as a source-to-source transformation.
Belief fusion, instead of AGM belief revision, was first proposed to solve the problem of inconsistency, that arise from repetitive application of the operation when agents' knowledge were amalgamated. However in ...
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The integration of preferences into answer set programming constitutes an important practical device for distinguishing certain preferred answer sets from non-preferred ones. To this end, we elaborate upon rule depend...
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The integration of preferences into answer set programming constitutes an important practical device for distinguishing certain preferred answer sets from non-preferred ones. To this end, we elaborate upon rule dependency graphs and their colorings for characterizing different preference handling strategies found in the literature. We start from a characterization of (three types of) preferred answer sets in terms of totally colored dependency graphs. In turn, we exemplarily develop an operational characterization of preferred answer sets in terms of operators on partial colorings for one particular strategy. In analogy to the notion of a derivation in proof theory, our operational characterization is expressed as a (non-deterministically formed) sequence of colorings, gradually turning an uncolored graph into a totally colored one.
This paper aims at presenting the application of first-order logic machine learning techniques to two document domains in order to learn rules for recognizing the semantic role of their logical components. Specificall...
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ISBN:
(纸本)9783540201199
This paper aims at presenting the application of first-order logic machine learning techniques to two document domains in order to learn rules for recognizing the semantic role of their logical components. Specifically, the multistrategy incremental learning system INTHELEX has been applied to multi-format scientific papers and documents concerning European films from the 20's and 30's. The challenge comes from the different levels of formatting standards in these domains: from (more or less) standardized layouts, in scientific papers, to documents with almost no standard, in historical cultural heritage material. Experimental results in both domains and a comparison with the Progol system assess the advantages that the exploitation of INTHELEX can yield.
A sound and complete sequent calculus for skeptical consequence in predicate default logic is presented. While skeptical consequence is decidable in the finite propositional case, the move to predicate or infinite the...
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ISBN:
(纸本)3540404945
A sound and complete sequent calculus for skeptical consequence in predicate default logic is presented. While skeptical consequence is decidable in the finite propositional case, the move to predicate or infinite theories increases the complexity of skeptical reasoning to being Π11-complete. This implies the need for sequent rules with countably many premises, and such rules are employed.
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