“…Intelligent systems have been successfully applied for the solution of a variety of difficult practical problems, such as medical diagnosis [1][2][3][4][5][6], intrusion detection [7], network traffic anomalies detection [8], multisensor battlefield reconnaissance simulation [9], local semantic indexing for resource discovery on overlay networks [10], distributed reasoning for context-aware service [11] and real-time water demand management [12]. Given a problem, its solving difficulty can be considered from different viewpoints, for example, from the human and the computational viewpoint.…”