A visual edition tool for design and verification of knowledge in rule-based systems

In order to address problems encountered in the design of rule-based and expert systems the paper discusses a proposal of a new approach to rule-based system design and verification using an integrated CASE tool supporting visual design of rule-based systems. The Mirella tool allows for dynamic on-line specification of components of the knowledge with simultaneous analysis of the rule-based system during the design phase. The main idea is to move the design procedure to a more abstract, logical level, where knowledge specification is based on use of abstract rule representation, called extended Tabular Trees, supported by Mirella CASE tool. It consists of visual design environment integrated with Prolog-based analysis and verification engine. Along with editor's built in on-line checking capabilities it improves system performance and safety. Selected implementation aspects are also highlighted. The environment is implemented in ANSI C in the GNU/Linux environment using Gtk/GNOME/SWI-Prolog development platform. This makes it both efficient and portable. The tool has a multilayer, multimodule architecture which gives it flexibility and allows future extensions.