expert system 
noun Computing
A piece of software which uses databases of expert knowledge to offer advice or make decisions in such areas as medical diagnosis.Similarly, non-biological entities such as expert systems, computer viruses or artificial intelligence could conceivably be considered to be ‘alive’....
- Unlike other artificial intelligence systems, like medical expert systems, COG was meant to test theories of human cognition and developmental psychology.
- An inference engine is the component of an expert system that applies a knowledge base to current data to arrive at a conclusion.