Fundamental to reasoning about actions and beliefs is the projection problem: to decide what is believed after a sequence of actions is performed. Progression is one widely applied technique to solve this problem. In this paper we propose a novel framework for computing progression in the epistemic situation calculus. In particular, we model an agent’s preferential belief structure using condit...

In 2], Reiter presents a formalism for database updates speciication. He uses the \situation calculus", that is, many-sorted rst-order languages for representing knowledge about dynamically changing worlds that evolve through diierent states when actions are executed. In these worlds, properties of their objects depend on the current state of the world. These properties are called uents and cor...

In this paper we study the ramification problem in the setting of time-owl. Standard solutions from the literature on reasoning about action are inadequate because they rely on the assumption that fluents persist, and actions have effects on the next situation only. In this paper we provide a solution to the ramification problem based on an extension of the situation calculus and the work of Mc...

This paper explores different techniques for explanation within the framework of the situation calculus, using the so-called stolen car problem as its main example. Two approaches to explanation are compared: the deductive approach usually found in the literature, and a less common abductive approach. Both approaches are studied in the context of two different styles of representation.

We propose a theory for describing, reasoning about, and simulating transaction models that relax some of the ACID properties of classical transactions. Such models have been proposed for database applications involving long-lived, endless, and cooperative activities. Our approach appeals to non-Markovian theories, in which one may refer to past states other than the previous one. We illustrate...

Among the most frequent reasoning tasks in the situation calculus are projection queries that query the truth of conditions in a future state of affairs. However, in long running action sequences solving the projection problem is complex. The main contribution of this work is a new technique which allows the length of the action sequences to be reduced by reordering independent actions and remo...

A sound and complete approach for encoding the action description language A developed by M. Gelfond and V. Lifschitz in an equational logic program is given. Our results allow the comparison of the resource-oriented equational logic based approach and various other methods designed for reasoning about actions, most of them based on variants of the situation calculus, which were also related to...

We define the class of e-bounded theories in the epistemic situation calculus, where the number of fluent atoms that the agent thinks may be true is bounded by a constant. Such theories can still have an infinite domain and an infinite set of states. We show that for them verification of an expressive class of first-order μ-calculus temporal epistemic properties is decidable. We also show that ...

We propose a theory for reasoning about actions based on order-sorted predicate logic where one can consider an elaborate taxonomy of objects. We are interested in the projection problem: whether a statement is true after executing a sequence of actions. To solve it we design a regression operator that takes advantage of well-sorted unification between terms. We show that answering projection q...

Knowledge, Belief, and Noisy Sensing in the Situation Calculus Patricio D. Simari Master of Science Graduate Department of Computer Science University of Toronto 2004 The extension to the situation calculus presented by Bacchus et al. formalizes the concept of noisy actions and shows how an agent can update its beliefs, which are modeled probabilistically, when relying on noisy sensors and effe...