Structural causal models offer a popular framework for exploring causal concepts. However, due to their limited expressiveness, structural models have difficulties coping with such concepts as actual (event-to-event) causation. In this paper, we propose a new type of causal model, based on embedding structural considerations in the language of situation calculus. By using situation calculus as ...

We add branching time to the linear discrete event calculus, which yields a formalism for commonsense reasoning that combines the benefits of the situation calculus and the event calculus. We characterize the precise relationship between the linear and branching versions of the discrete event calculus, and prove that a restricted version of the branching discrete event calculus is equivalent to...

When agents like mobile robots make observations while carrying out a course of actions, a formalization of the observed information is needed in order to reason about it. When doing so in the situation calculus, a seemingly straightforward approach turns out to be inappropriate since it leads to unintended results and has an unfortunate sensitivity with respect to different forms of successor ...

When reasoning about actions and sensors in realistic domains, the ability to cope with uncertainty often plays an essential role. Among the approaches dealing with uncertainty, the one by Bacchus, Halpern and Levesque, which uses the situation calculus, is perhaps the most expressive. However, there are still some open issues. For example, it remains unclear what an agent’s knowledge base woul...

Exploiting the analogy between exemplar models and population coding schemes, we characterize, by means of information theoretic tools, the efficiency of a large but finite population of cells coding for a discrete set of categories (e.g. vowels). The optimal code is shown to typically allocate more cells to class boundaries than to regions further apart. We then discuss the predicted perceptua...

We consider the problem of designing reliable and confidential lattice codes, known as wiretap lattice codes, for fast fading channels. We identify as code design criterion for finite lattice constellations a finite sum of inverse of algebraic norms, in fact the analogous for finite sums of the known criterion for infinite constellations, which motivates us to study totally real number fields w...

Pregnancy and delivery is one of the main causes in the female body weight alteration, especially with obesity. This alteration in body weight has a significant effect not only for a femine beauty standpoint, but also for more important reproductive functions in postpartum. For the actual condition of the maternal body weight alteration and its clinical significance, we made the various analysi...

ion in Situation Calculus Action Theories Bita Banihashemi York University Toronto, Canada [email protected] Giuseppe De Giacomo Sapienza Università di Roma Roma, Italy [email protected] Yves Lespérance York University Toronto, Canada [email protected]

This article presents a situation calculus formalism featuring events as primary and the usual actions as a special case. Events that are not actions are called internal events and actions are called external events. The effects of both kinds of events are given by effect axioms of the usual kind. The actions are assumed to be performed by an agent as is usual in situation calculus. An internal...

Imposing a markovian condition on the situation calculus enables the embedding of situation calculus theories into the DEVS (discrete event system speciication) modelling and simulation framework. DEVS has an algebraic formalism relying on classical systems theory, and has been used to good eeect in practical domains. The demonstrated correspondence between the situation calculus and DEVS is ba...