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15
Updating action domain descriptions
- in Proc. IJCAI
, 2005
"... How can an intelligent agent update her knowledge base about an action domain, relative to some conditions (possibly obtained from earlier observations)? We study this question in a formal framework for reasoning about actions and change, in which the meaning of an action domain description can be r ..."
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Cited by 24 (5 self)
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How can an intelligent agent update her knowledge base about an action domain, relative to some conditions (possibly obtained from earlier observations)? We study this question in a formal framework for reasoning about actions and change, in which the meaning of an action domain description can be represented by a directed graph whose nodes correspond to states and whose edges correspond to action occurrences. We define the update of an action domain description in this framework, and show among other results that a solution to this problem can be obtained by a divide-and-conquer approach in some cases. We also introduce methods to compute a solution and an approximate solution to this problem, and analyze the computational complexity of these problems. Finally, we discuss techniques to improve the quality of solutions. 1
On the modularity of theories
- In Advances in Modal Logic
"... abstract. In this paper we give the notion of modularity of a theory and analyze some of its properties, especially for the case of action theories in reasoning about actions. We propose algorithms to check whether a given action theory is modular and that also make it modular, if needed. Completene ..."
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Cited by 15 (13 self)
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abstract. In this paper we give the notion of modularity of a theory and analyze some of its properties, especially for the case of action theories in reasoning about actions. We propose algorithms to check whether a given action theory is modular and that also make it modular, if needed. Completeness, correctness and termination results are demonstrated. 1
Domain descriptions should be modular
"... In this work we address the problem of what a good domain description for reasoning about actions should look like. We establish some postulates concerning this sore spot and point out the problems that arise when they are violated. Such problems can be overcome with the algorithms we propose. ..."
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Cited by 15 (11 self)
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In this work we address the problem of what a good domain description for reasoning about actions should look like. We establish some postulates concerning this sore spot and point out the problems that arise when they are violated. Such problems can be overcome with the algorithms we propose.
Cohesion, coupling and the meta-theory of actions
- In Proc. IJCAI’05, 442– 447
, 2005
"... herzig,ivan¢ In this work we recast some design principles commonly used in software engineering and adapt them to the design and analysis of domain descriptions in reasoning about actions. We show how the informal requirements of cohesion and coupling can be turned into consistency tests of several ..."
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Cited by 11 (10 self)
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herzig,ivan¢ In this work we recast some design principles commonly used in software engineering and adapt them to the design and analysis of domain descriptions in reasoning about actions. We show how the informal requirements of cohesion and coupling can be turned into consistency tests of several different arrangements of modules. This gives us new criteria for domain description evaluation and clarifies the link between software and knowledge engineering in what concerns the meta-theory of actions. 1
On Action Theory Change
"... As historically acknowledged in the Reasoning about Actions and Change community, intuitiveness of a logical domain description cannot be fully automated. Moreover, like any other logical theory, action theories may also evolve, and thus knowledge engineers need revision methods to help in accommoda ..."
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Cited by 6 (5 self)
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As historically acknowledged in the Reasoning about Actions and Change community, intuitiveness of a logical domain description cannot be fully automated. Moreover, like any other logical theory, action theories may also evolve, and thus knowledge engineers need revision methods to help in accommodating new incoming information about the behavior of actions in an adequate manner. The present work is about changing action domain descriptions in multimodal logic. Its contribution is threefold: first we revisit the semantics of action theory contraction proposed in previous work, giving more robust operators that express minimal change based on a notion of distance between Kripke-models. Second we give algorithms for syntactical action theory contraction and establish their correctness with respect to our semantics for those action theories that satisfy a principle of modularity investigated in previous work. Since modularity can be ensured for every action theory and, as we show here, needs to be computed at most once during the evolution of a domain description, it does not represent a limitation at all to the method here studied. Finally we state AGM-like postulates for action theory contraction and assess the behavior of our operators with respect to them. Moreover, we also address the revision counterpart of action theory change, showing that it benefits from our semantics for contraction. 1.
I.: A propositional typicality logic for extending rational consequence
- Trends in Belief Revision and Argumentation Dynamics, Studies in Logic – Logic and Cognitive Systems
, 2013
"... abstract. We introduce Propositional Typicality Logic (PTL), a logic for reasoning about typicality. We do so by enriching classical proposi-tional logic with a typicality operator of which the intuition is to capture the most typical (or normal) situations in which a given formula holds. The semant ..."
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Cited by 3 (2 self)
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abstract. We introduce Propositional Typicality Logic (PTL), a logic for reasoning about typicality. We do so by enriching classical proposi-tional logic with a typicality operator of which the intuition is to capture the most typical (or normal) situations in which a given formula holds. The semantics is in terms of ranked models as studied in KLM-style preferential reasoning. This allows us to show that KLM-style rational consequence relations can be embedded in our logic. Moreover we show that we can define consequence relations on the language of PTL itself, thereby moving beyond the propositional setting. Building on the exist-ing link between propositional rational consequence and belief revision, we show that the same correspondence holds in the case of rational con-sequence and belief revision defined on the language of PTL. Finally we also investigate different notions of entailment for PTL and propose two appropriate candidates.
Interpolation Properties of Action Logic: Lazy-formalization to the Frame Problem
"... This paper makes a contribution to the meta-theory of reasoning about action. We present two interpolation properties of action logic. We show that the frame axioms which are required for answering a query involve only the objects which are relevant to the query and action description. Moreover, ..."
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This paper makes a contribution to the meta-theory of reasoning about action. We present two interpolation properties of action logic. We show that the frame axioms which are required for answering a query involve only the objects which are relevant to the query and action description. Moreover, if the action description is expressed by normal form, the required frame axioms depend on only the query itself. Therefore the frame problem may be mitigated by localizing descriptions and postponing the listing of frame axioms till a query occurs. This offers a pragmatic solution to the frame problem. This solution does not rest on any meta-hypotheses most existing solutions to the frame problem rely on.
Comparing action descriptions based on semantic preferences
- Annals of Mathematics and Artificial Intelligence
"... Abstract. Incorporating new information into a knowledge base is an important problem which has been widely considered. In this paper, we study the problem in a formal framework for reasoning about action and change, in which action domains are described in an action language that has a transition-b ..."
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Cited by 2 (1 self)
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Abstract. Incorporating new information into a knowledge base is an important problem which has been widely considered. In this paper, we study the problem in a formal framework for reasoning about action and change, in which action domains are described in an action language that has a transition-based semantics. Going beyond previous works, we consider (i) a richer action language that allows for non-deterministic, and concurrent actions, as well as the representation of indirect effects and dependencies between fluents, (ii) more general updates than elementary statements, and, most importantly, (iii) meta-level knowledge, such as observations, assertions, or general domain properties that remain invariant under change, expressed in an action query language. For this setting, we formalize a notion of update of an action domain description, relative to a generic preference relation on action domain descriptions that selects most preferred solutions. We study semantic and computational aspects of this notion, where we establish basic properties of updates and a decomposition result that gives rise to a divide and conquer approach to computing solutions under certain conditions. Furthermore, we study the computational complexity of decision problems around computing solutions, both for the generic setting and for two particular preference relations, viz. set-inclusion and weight-based preference. While deciding the existence of solutions
Frame problem in dynamic logic
"... ABSTRACT. This paper provides a formal analysis on the solutions of the frame problem by using dynamic logic. We encode Pednault’s syntax-based solution, Baker’s state-minimization policy, and Gelfond & Lifchitz’s Action Language A in the propositional dynamic logic (PDL). The formal relationshi ..."
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Cited by 2 (0 self)
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ABSTRACT. This paper provides a formal analysis on the solutions of the frame problem by using dynamic logic. We encode Pednault’s syntax-based solution, Baker’s state-minimization policy, and Gelfond & Lifchitz’s Action Language A in the propositional dynamic logic (PDL). The formal relationships among these solutions are given. The results of the paper show that dynamic logic, as one of the formalisms for reasoning about dynamic domains, can be used as a formal tool for comparing, analyzing and unifying logics of action.
