C. Baral, M. Gelfond, and A. Provetti. Reasoning about actual and hypothetical occurrences of concurrent and non-deterministic actions. In Proceedings AAAI Spring Symposium, 1995.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....S 0 and McCain and Turner s approach [21] permit exactly the same inferences. For another large class of reasoning domains, we proved that S 0 is equivalent to Baral and Gelfond s approach based on the action description language L 3 (an extension of Lifschitz and Gelfond s well known language A [3]; also, we have made an informal comparison that makes clear that Lin s recent approach [19, 20] is largely identical to S 0 . We also provide examples of reasoning domains for which S 0 is not equivalent to either McCain and Turner s or Baral and Gelfond s approach, and for which it gives better ....

.... [28] are to be classified among the causal approaches, since they too, are based on explicitly distinguishing between what is caused to hold and what actually holds in a model (though the word caused is not always employed) Next we compare S 0 to two ADL approaches: Baral and Gelfond s L 3 [3] and McCain and Turner s [21] Theory of Ramifications and Qualifications. L 3 is an extension of the well known language A [8] that can deal with concurrent actions, incomplete specification of actions and incomplete knowledge on the order of the observations in time; it cannot at all deal with ....

[Article contains additional citation context not shown here]

C. Baral, M. Gelfond, and A. Provetti. Reasoning about actual and hypothetical occurrences of concurrent and non-deterministic actions. In Proceedings AAAI Spring Symposium, 1995.

....Tmt and b) there is an M j= Tc with Ab 1 g (M) Ab 2 f (M) then 1. M 2 S 0 (T c ) Res 4 C (E; S) fS 0 g; M = S; S 0 ) 2. S 0 2 Res 4 C (E; S) there exists an M with M 2 S 0 (T c ) M = S; S 0 ) Baral and Gelfond s L 3 and S 0 Baral and Gelfond s (BG) approach [3, 2] which is based on their ADL L 3 , consists of domain descriptions D written in L 3 . We compared our theories Tc to domain descriptions D in exactly the same way as we compared them to theories Tmt of MT s approach: we will first give an example of a reasoning domain where S 0 gives better ....

....said to be ambiguous. The correspondence relations and = are introduced in definitions 6 and 7 In these definitions we will deviate a little from our usual notation: we will denote tokens for event, fluent and time name constants using regular (non bold,non capital) symbols as is done in [2]. 16 Definition 9 The method M 0 applied to a domain theory Tc consists of the following steps: 1. Circumscribe Ca in Tc with Ho (and all other functions and predicates) fixed and let the resulting theory be T 0 c : T 0 c = Circum(T c ; Ca) 2. Now add the causation and persistence ....

C. Baral and M. Gelfond. Reasoning about actual and hypothetical occurrances of concurrent and non-deterministic actions. Available via ftp://ftp.newcastle.edu.au/pub/papers/nrac95/baral.final.ps, 1995.

....of I 0 . In another paper [9] we show how S 0 can be applied to solve many of the notorious problems in nonmonotonic reasoning. In that paper, we also give the theorems and distinguishing examples that relate S 0 to the existing causal approaches and the more recent systematic approaches [7, 10] which from our point of view are just special cases of the causal ones. In this paper, all nonmonotonic methods are given as model selection criteria; in the other paper, we also discuss more syntactically oriented variations. The remainder of this paper is structured as follows: first, we ....

....a) or b) the format in which T B must be in order for the theorem to hold, rules out domain descriptions where these problems may occur. Concerning S 0 , we proved [11] equivalences between restricted versions of S 0 and the approaches of McCain and Turner [14] and Baral and Gelfond s L 3 [10] 6 . It becomes clear at first glance that Lin s recent approach [13] is almost identical to S 0 . For the causal approaches of Morgenstern and Stein [15] and Lifschitz, Haugh and Rabinov [12] we give examples [9] showing that they sometimes yield the wrong results. We take all this as evidence ....

C. Baral, M. Gelfond, and A. Provetti. Reasoning about actual and hypothetical occurrences of concurrent and non-deterministic actions. In Proceedings AAAI Spring Symposium, 1995.

....(B1) 7. Each axiom in T b is of one of the forms occurring in conditions 2 6 above. Each axiom in Tnc is of one of the forms occurring in conditions 2 5 above. between a restriction of S 0 and the approach based on Baral Gelfond s actiondescription language L 3 (an extension of Lifschitz A) [2]. For the causal approaches of Morgenstern Stein, Geffner and Lifschitz, Haugh and Rabinov [5, 7, 9, 16] we give examples of reasoning domains where our approach gives better results than they do. We take this as evidence that S 0 works well for wide classes of causal theories. Note that S 0 can ....

C. Baral, M. Gelfond, and A. Provetti. Reasoning about actual and hypothetical occurrences of concurrent and non-deterministic actions. In Proceedings AAAI Spring Symposium, 1995.

....ones. We have proven that some recent causal and action description language based approaches are equivalent to various restrictions of S 0 specifically, we proved equivalences between restricted versions of S 0 and the approaches of McCain and Turner [1995] and Baral and Gelfond s L 3 [ Baral et al. 1995 ] also, we have made an informal comparison that makes clear that Lin s recent approach [ Lin, 1995; 1996 ] is largely identical to S 0 . For the other existing causal approaches specifically, those of Morgenstern and Stein [1988] Geffner [1990] and Lifschitz, Haugh and Rabinov [ Haugh, ....

.... 1995 ] are to be classified among the causal approaches, since they too, are based on explicitly distinguishing between what is caused to hold and what actually holds in a model (though the word caused is not always employed) Next we compare S 0 to two ADL approaches: Baral and Gelfond s L 3 [ Baral et al. 1995 ] and McCain and Turner s [1995] Theory of Ramifications and Qualifications. L 3 is an extension of the wellknown language A [ Sandewall and Shoham, 1995 ] that can deal with concurrent actions, incomplete specification of actions and incomplete knowledge on the order of the observations in time; ....

[Article contains additional citation context not shown here]

C. Baral, M. Gelfond, and A. Provetti. Reasoning about actual and hypothetical occurrences of concurrent and non-deterministic actions. In Proceedings AAAI Spring Symposium, 1995.

....of how to formalize actions whose effect is a disjunction of fluents. Recently, some authors have, either explicitly or implicitly, begun to take up this question [17, 25] A special case of this question concerns the more well known issue of representing actions with non deterministic effects [1, 17, 24]. If an event occurs that sets the value of a proposition X to true, where X j Y Z, it is not immediately clear what should happen: should we exempt both Y and Z from persistence, or should we keep as much persistence as is logically consistent In example 5 we implicitly chose the latter option: ....

C. Baral and M. Gelfond. Reasoning about actual and hypothetical occurrances of concurrent and non-deterministic actions. In Proceedings First Workshop on Nonmonotonic Reasoning, Action and Change, 1995. Available via ftp://ftp.newcastle.edu.au/pub/papers/nrac95/baral.final.ps.

....Our description of these dynamic physical system domains will be based on the formalism of action languages. Such languages can be thought of as formal models of the part of the natural language that we use to describe the behavior of dynamic domains. For detail of research in such languages see [GL92, BGW, Tur97, BGP97]. We can represent an action language as the sum of two distinct parts: an action description language and an action 4 Figure 3: The functional plumbing schematic for the forward reaction control system. The fill, drain, check and relief valves, the electrical controls, and the instrumentation ....

Chitta Baral, Michael Gelfond, and Richard Watson. Reasoning About Actual and Hypothetical Occurrences of Concurrent and Non-deterministic Actions, in Theoretical Approaches to Dynamic Worlds, edited by Bertram Fronhofer and Remo Pareschi (to appear).

....are given. The translation is shown to be sound and complete for queries under Prolog and XSB. Computational examples are given which show the feasibility of this approach. 1 Introduction In recent years a considerable amount of research has been done in the area of action languages [BGW, Tur97, BGP97]. Over the past year we have been working under a contract with United Space Alliance to use such languages to model subsystems of the Space Shuttle. The goal of the work under the contract is to provide tools to help plan for correct operation of the Shuttle in situations with multiple failures. ....

Chitta Baral, Michael Gelfond, and Richard Watson. Reasoning About Actual and Hypothetical Occurrences of Concurrent and Non-deterministic Actions, in Theoretical Approaches to Dynamic Worlds, edited by Bertram Fronhofer and Remo Pareschi (to appear).

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