Narrative planners would be able to represent richer, more realistic story domains if they could use numeric variables for certain properties of objects, such as money, age, temperature, etc. Modern state-space narrative planners make use of causal links—structures that represent causal dependencies between actions—but there is no established model of a causal link that applies to actions with ...

The automatic derivation of heuristic functions for guiding the search for plans in large spaces is a fundamental technique in planning. The type of heuristics that have been considered so far, however, deal only with simple planning models where costs are associated with actions but not with states. In this work we address this limitation by formulating a more expressive planning model and a c...

In this paper we study the ramification problem in the setting of temporal databases. Standard solutions from the literature on reasoning about action are inadequate because they rely on the assumption that fluents persist, and because 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 ...

We clevelop a qualitative framework for temporal reasoning with incomplete information that features a modeling language based on rules and a semantics based on infinitesimal probabilities. The framework relates logical and probabilistical models, and accommodates in a natural way features that, have been found problematic in other models like nondeterminism, action qualifications, parallel act...

We present a distantly supervised system for extracting the temporal bounds of fluents (relations which only hold during certain times, such as attends school). Unlike previous pipelined approaches, our model does not assume independence between each fluent or even between named entities with known connections (parent, spouse, employer, etc.). Instead, we model what makes timelines of fluents c...

The phenomenon of movement arises whenever the same object occupies different positions in space at different times. Therefore a theory of movement must contain theories of time, space, objects, and position. We provide a theoretical basis for describing movement events in terms of the conditions for their occurrence, which refer to the holding or not holding of various positional fluents at di...

General action languages, like e.g. the Situation Calculus, use full classical logic to represent knowledge of actions and their effects in dynamic domains. Description Logics, on the other hand, have been developed to represent static knowledge with the help of decidable subsets of first order logic. In this paper, we show how to use Description Logic as the basis for a decidable yet still exp...

The TM-LPSAT planner can construct plans in domains containing atomic actions and durative actions; events and processes; discrete, real-valued, and interval-valued fluents; reusable resources, both numeric and interval-valued; and continuous linear change to quantities. It works in three stages. In the first stage, a representation of the domain and problem in an extended version of PDDL+ is c...

In this paper, we investigate bounded action theories in the situation calculus. A bounded action theory is one which entails that, in every situation, the number of object tuples in the extension of fluents is bounded by a given constant, although such extensions are in general different across the infinitely many situations. We argue that such theories are common in applications, either becau...