How to combine event stream reasoning with transactions for the semantic web

Event-Condition-Action languages are the commonly accepted para- digm to express and model the behavior of reactive systems. While numerous Event-Condition-Action languages have been proposed in the literature, differing e.g. on the expressivity of the language and on its operational behavior, existing Event-Condition-Action languages do not generally support the action compo- nent to be formulated as a transaction. In this paper, sustaining that it is important to execute transactions in reactive languages, we propose an Event-Condition- Transaction language, based on an extension of Transaction Logic. This exten- sion, called Transaction Logic with Events (T Rev ), combines reasoning about the execution of transactions with the ability to detect complex events. An impor- tant characteristic of T Rev is that it takes a choice function as a parameter of the theory, leaving open the behavioral decisions of the logic, and thereby allowing it to be suitable for a wide-spectrum of application scenarios like Semantic Web, multi-agent systems, databases, etc. We start by showing how T Rev can be used as an Event-Condition-Action language where actions are considered as transac- tions, and how to differently instantiate this choice function to achieve different operational behaviors. Then, based on a particular operational instantiation of the logic, we present a procedure that is sound and complete w.r.t. the semantics and that is able to execute T Rev programs