State-of-the-art on evolution and reactivity

This report starts by, in Chapter 1, outlining aspects of querying and updating resources on the Web and on the Semantic Web, including the development of query and update languages to be carried out within the Rewerse project. From this outline, it becomes clear that several existing research areas and topics are of interest for this work in Rewerse. In the remainder of this report we further present state of the art surveys in a selection of such areas and topics. More precisely: in Chapter 2 we give an overview of logics for reasoning about state change and updates; Chapter 3 is devoted to briefly describing existing update languages for the Web, and also for updating logic programs; in Chapter 4 event-condition-action rules, both in the context of active database systems and in the context of semistructured data, are surveyed; in Chapter 5 we give an overview of some relevant rule-based agents frameworks

State-of-the-art on evolution and reactivity

This report starts by, in Chapter 1, outlining aspects of querying and updating resources on the Web and on the Semantic Web, including the development of query and update languages to be carried out within the Rewerse project. From this outline, it becomes clear that several existing research areas and topics are of interest for this work in Rewerse. In the remainder of this report we further present state of the art surveys in a selection of such areas and topics. More precisely: in Chapter 2 we give an overview of logics for reasoning about state change and updates; Chapter 3 is devoted to briefly describing existing update languages for the Web, and also for updating logic programs; in Chapter 4 event-condition-action rules, both in the context of active database systems and in the context of semistructured data, are surveyed; in Chapter 5 we give an overview of some relevant rule-based agents frameworks

Iterated logic program updates

The eld of theory update has seen some improvement, in what regards updating, by allowing desired updates to be speci ed by update programs. The updating of models is governed by update rules, as well as by inertia applied to those literals not directly a ected by the update program. Though this is important, it remains necessary to tackle too the updating of theories speci ed by programs. In this paper we explore logic program updates, namely how to exert inertia on program rules rather than on the literals of their models. We de ne program updates and characterize them semantically, both for the 2-valued and the 3-valued cases. We also de ne iterated logic program updating, a crucial notion inasmuch as it allows us to conceive what it is to successively update one program by another, and so to prescribe the evolution of knowledge bases by means of updates

Iterated Logic Program Updates

The field of theory update has seen some improvement, in what regards updating, by allowing desired updates to be specified by update programs. The updating of models is governed by update rules, as well as by inertia applied to those literals not directly affected by the update program. Though this is important, it remains necessary to tackle too the updating of theories specified by programs. In this paper we explore logic program updates, namely how to exert inertia on program rules rather than on the literals of their models. We define program updates and characterize them semantically, both for the 2-valued and the 3-valued cases. We also define iterated logic program updating, a crucial notion inasmuch as it allows us to conceive what it is to successively update one program by another, and so to prescribe the evolution of knowledge bases by means of updates