Simulation, Information systems, Object-oriented programming, Nested models, Nested theories

The paper is oriented to a special way of solving a certain contradiction present in the simulation of the information systems: on one hand the information system is a complex and rich physical paper existing in time and composed of physical units (computers) connected by physical links, and on the other hand it handles information that is also complex and rich but in general quite different from that governing the physical aspects of the system. A description of a simple but sophisticated method of solving the problem is presented, based on nesting two theories formalized with use of the object-oriented programming representation of knowledge, each of them representing one view to the simulated information system(s). A simple example is added.