The situation calculus is one of the most established formalisms for reasoning about action and change. In this paper we will review the basics of Reiter’s version of the situation calculus, show how knowledge and time have been addressed in this framework, and point to some of the weaknesses of the situation calculus with respect to time. We then present a modal version of the situation calcul...

A fundamental aspect of general reasoning about physical systems is qualitative reasoning about continuous processes. The situation calculus is proposed as a framework for qualitative reasoning with some desirable properties that are less evident in the traditional framework, qualitative physics. However, in order to handle qualitative reasoning about continuous properties, we extend the concur...

A narrative is a course of real events about which we might have incomplete information. Formalisms for reasoning about action may be broadly divided into those which are narrative-based, such as the Event Calculus of Kowalski and Sergot, and those which reason on the level of hypothetical sequences of actions, in particular the Situation Calculus. This paper bridges the gap between these types...

Concurrent events are treated merely by not forbidding them. Narrative is treated as a collection of situations and events and relations among them. Narrative is easier than planning, because it does not require that the effects of events be guaranteed. Prediction is harder than planning, because it requires that the actions be inferred from the motives of the actors.

We consider the problem of planning in complex domains where actions are stochastic, non-instantaneous, may occur concurrently, and time is represented explicitly. Our approach is based on the situation calculus based language Golog. Instead of general search for a sequence of actions, as in classical planning, we consider the problem of computing a deterministic, sequential program (with stoch...

In this paper we provide new evidence about the relationship between financial crises and economic situation for different countries which belong to the OECD and emergent economies of Latin America and Asia. The results show new support to the different influence of economic situation according to the type of financial crises. Aggregate data and panel techniques are used taking into account the...

We define these region of time as a regime whose mean and variance are explicitly different from other region of time. This regime can represent economic situation. If we can figure out this regime, in other words, current economic situation, we can forecast better than using constant mean and variance. In this project, we would like to construct this regime and utilize it for the stock forecas...

I present a language for specifying planning problems in which there are external events, that is, events beyond the direct control of the planner which may happen while a plan is being executed. The language is based on Miller and Shanahan’s representation of narratives in the situation calculus. I describe an implemented planner that produces correct plans for this language, and discuss how s...