On Computing Extensions and Restrictions of Information Systems Noting Some Order Properties

The aim of this paper is to give the basic view on computing consistent extensions and restrictions of information systems noting some order properties of information system families. Information systems are understood in the Pawlak’s sense as the systems of knowledge representation. The extension appears if we add to the original information system some new objects corresponding to the known attribute values. Analogously, the restriction appears if we remove from the original information system some objects. Presented observations enable us to find proper descriptions (preserving some features) of concurrent systems whose behavior is represented by means of information systems.