Mobal is a sophisticated system for developing operational models of
application domains. It integrates a manual knowledge acquisition and 
inspection environment, a powerful inference engine, machine learning 
methods for automated knowledge acquisition, and a knowledge revision tool.

By using Mobal's knowledge acquisition environment, you can
incrementally develop a model of your domain in terms of logical facts
and rules.  You can inspect the knowledge you have entered in text or
graphics windows, augment the knowledge, or change it at any time.
The built-in inference engine can immediately execute the rules you
have entered to show you the consequences of your inputs, or answer
queries about the current knowledge.  Mobal also builds a dynamic sort
taxonomy from your inputs.  If you wish, you can use machine learning 
methods to automatically discover additional rules based on the facts
that you have entered, or to form new concepts.  If there are
contradictions in the knowledge base due to incorrect rules or facts,
there is a knowledge revision tool to help you locate the problem and fix
it.