In this work we study action theories of the situation calculus such that the initial KB is a generalized database with equality constraints (GFDBs). We show that GFDBs characterize the class of definitional KBs and that they are closed under progression. We also show that, under conditions, generalized projection queries can be decided based on an induced transition system and evaluation of lo...

Flat transactions with savepoints are a variation of the classical flat transactions that allows the user to go undo work done so far back to a certain point within the transaction. This is as opposed to pure classical flat transactions that either commit to whole work done so far or undo it. Recently, this mechanism is being offered by some major database products. Their semantics, however, se...

In many real-world applications, temporal information is often imprecise about the temporal location of events (indeterminacy) and comes at different granularities. Formalisms for reasoning about events and change, such as the Event Calculus (EC) and the Situation Calculus, do not usually provide mechanisms for handling such data, and very little research has been devoted to the goal of extendi...

The Situation Calculus and the Fluent Calculus are successful action formalisms that share many concepts. But until now there is no formal relation between the two calculi that would allow to formally analyze the relationship between the two approaches as well as between the programming languages based on them, Golog and FLUX. Furthermore, such a formal relation would allow to combine Golog and...

The Situation Calculus is a logic of time and change in which there is a distinguished initial situation S0 and all other situations arise from the different sequences of actions that might be performed starting in the initial one. Within this framework, it is difficult to incorporate the notion of an occurrence, since all situations after the initial one are hypothetical. These occurrences are...

Communicative language use largely entails regular patterns consisting of pre-constructed phrases or sequences. These sequences have been examined by many researchers to find the situation-based formulas which may help L2 learners follow a possibly more target-like speaking system. This study, therefore, explored two categories of formulaic expressions including speech formulas and situation-bo...

objective: an important factor in the prevention of industrial accidents is the employees’ ability to maintain their awareness of the work situation, understand the information it holds, and predict the development of the situations. in this study, we examined the role of work stress and sleepiness in predicting work situation awareness among workers.  methods: the present study was a cross-sec...

We present a novel theory of action and change capable of dealing with discord between an agent’s beliefs and the results of its sensing. Previous work by Scherl and Levesque [9] and Shapiro et al. [10] have given accounts of iterated belief update and revision, and the ability to deal with mistaken beliefs. However, they assume that all actions, including exogenous actions beyond the agent’s c...

We present a novel theory of action and change capable of dealing with discord between an agent’s beliefs and the results of its sensing. Previous work by Scherl and Levesque [9] and Shapiro et al. [10] have given accounts of iterated belief update and revision, and the ability to deal with mistaken beliefs. However, they assume that all actions, including exogenous actions beyond the agent’s c...