L.R. Missiaen, M. Bruynooghe, and M. Denecker. Abductive planning with event calculus. Internal report, Department of Computer Science, K.U.Leuven, 1992.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....in logic programming in order to solve planning problems in the Event Calculus [65] In this approach, abduction solves a planning goal by explaining it by an ordered sets of events a plan that entails the planning goal. This approach was further explored by Shanahan [110] Missiaen et al. [72, 71], Denecker [21] Jung [48] and recently in [59, 60] Kakas and Mancarella showed the application of abduction in logic programming for deductive database updating and knowledge assimilation [53, 55] The application of abduction to diagnosis has been studied in [10, 11] within an abductive logic ....

L.R. Missiaen, M. Bruynooghe, and M. Denecker. Abductive planning with event calculus. Internal report, Department of Computer Science, K.U.Leuven, 1992.

....a class of possible states of a airs in which the observation is valid. In the context of temporal reasoning, Eshghi [14] was the rst to use abduction. He used abduction to solve planning problems in the Event Calculus [28] This approach was further explored by Shanahan [48] Missiaen et al. [37, 34], 11] and [20] Planning in the event calculus can be seen as a variant of reasoning from observations to causes. Here, the observation corresponds to the desired nal state. The e ect rules describing e ects of actions provide the causality information. The causes are the actions to be performed ....

....that transforms the initial state into the goal state. The predicates describing this sequence are happens and ; they are subject of the planning search and hence they are open predicates in any EC describing a planning domain. As reported in [34] early abductive planning systems ( 14] 48] [37]) sometimes generated erroneous partial plans, in which two interfering actions (such as ipping a switch) are assumed to be unrelated in time. While these erroneous plans logically entail the desired nal state, linearisations of these plans do not in general. As a consequence, real execution of ....

L.R. Missiaen, M. Bruynooghe, and M. Denecker. Abductive planning with event calculus. Internal report, Department of Computer Science, K.U.Leuven, 1992.

....cannot become ground. A procedure for planning should be able to cope with such situations. This condition is not satis ed by the abductive procedure de ned in [11] In the past, special abductive procedures for temporal reasoning with abductive event calculus have been presented ( 8] 20] [16, 17]) However, as the three authors argue, the treatment of constraints in [8] and the treatment of non ground abductive failure goals in [20] 16, 17] can be very inecient. The abductive procedure SLDNFA presented in this paper, provides an improved treatment of non ground abductive atoms. We have ....

.... de ned in [11] In the past, special abductive procedures for temporal reasoning with abductive event calculus have been presented ( 8] 20] 16, 17] However, as the three authors argue, the treatment of constraints in [8] and the treatment of non ground abductive failure goals in [20] [16, 17] can be very inecient. The abductive procedure SLDNFA presented in this paper, provides an improved treatment of non ground abductive atoms. We have proven its sound and completeness. Although the inspiration for the design of SLDNFA stems from temporal reasoning, we formulate it in full ....

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L. Missiaen, M. Bruynooghe, and M. Denecker. Abductive planning with event calculus. Internal report, Department of Computer Science, K.U.Leuven, 1992.

....in 1 logic programming in order to solve planning problems in the Event Calculus [56] In this approach, abduction solves a planning goal by explaining it by an ordered sets of events a plan that entails the planning goal. This approach was further explored by Shanahan [97] Missiaen et al. [62, 61], Denecker [16] Jung [41] and recently in [51, 52] Kakas and Mancarella showed the application of abduction in logic programming for deductive database updating and knowledge assimilation [46, 48] The application of abduction to diagnosis has been studied in [8, 9] within an abductive logic ....

L.R. Missiaen, M. Bruynooghe, and M. Denecker. Abductive planning with event calculus. Internal report, Department of Computer Science, K.U.Leuven, 1992.

....become ground. A procedure for planning should be able to cope with such situations. This condition is not satisfied by the abductive procedure defined in [7] In the past, special abductive procedures for temporal reasoning with abductive event calculus have been presented ( 3] 12] Recently, [9, 10] described an implementation of such a planner based on a special purpose abductive procedure. However, for the procedures in [3] and [12] no formalisation of the procedure is given and soundness and completeness results are lacking. In [9, 10] the abductive procedure is designed for a specific ....

....calculus have been presented ( 3] 12] Recently, 9, 10] described an implementation of such a planner based on a special purpose abductive procedure. However, for the procedures in [3] and [12] no formalisation of the procedure is given and soundness and completeness results are lacking. In [9, 10], the abductive procedure is designed for a specific class of planning problems, but is unsound in the general case. Moreover, as the three authors argue, the treatment of non ground abductive failure goals can be very inefficient. As a first contribution, we present in section 2 an improved ....

[Article contains additional citation context not shown here]

L.R. Missiaen, M. Bruynooghe, and M. Denecker. Abductive planning with event calculus. Internal report, Department of Computer Science, K.U.Leuven, 1992.

....a class of possible states of affairs in which the observation is valid. In the context of temporal reasoning, Eshghi [13] was the first to use abduction. He used abduction to solve planning problems in the Event Calculus [23] This approach was further explored by Shanahan [43] Missiaen et al. [32, 29], 11] and [18] Planning in the event calculus can be seen as a variant of reasoning from observations to causes. Here, the observation corresponds to the desired final state. The effect rules describing effects of actions provide the causality information. The 1 If E contains free variables, ....

....the initial into the goal state. The predicates describing this sequence are happens and ; they are subject of the planning search; a fortiori these predicates are open predicates in the EC describing the planning domain. As reported in [29] early abductive planning systems ( 13] 43] [32]) sometimes generated erroneous partial plans, in which two interfering actions (such as flipping a switch) are assumed to be unrelated in time. While these erroneous plans logically entail the desired final state, linearisations of these plans did not in general. As a consequence, real execution ....

L.R. Missiaen, M. Bruynooghe, and M. Denecker. Abductive planning with event calculus. Internal report, Department of Computer Science, K.U.Leuven, 1992.

....about r=1. The problem now is that the set fr(a)g is incomplete: indeed, it is easy to see that the resolution of the goal with r(a) will ultimately lead to the abduction of r(b) Hence, the failure tree cannot be computed completely at this point of the computation. The procedures of [41] and [34] solve this problem by storing all negative literals for which a failure tree is to be computed and rebuilding their failure trees each time a new fact is abduced. As indicated by the authors, this may introduce a serious overhead. SLDNFA avoids this by interleaving the computation of this failure ....

....that with any SLDNFA derivation, one can associate an SLDNF refutation in P Delta generating the same answer substitution, and then relying on the soundness of SLDNF. Though at first sight this may seem easier, there are definitely a number of tedious snakes under the grass (see for example [34]) Moreover this technique is also substantially weaker. Using the proof tree, we obtain the additional result that the conjunction of the leaves of the proof tree (the conjunction consisting of ( Delta) and all remaining constraints) imply ( Q) under the completion of the incomplete program P ....

L.R. Missiaen, M. Bruynooghe, and M. Denecker. Abductive planning with event calculus. Internal report, Department of Computer Science, K.U.Leuven, 1992.

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