Inference Rules of Explanation system

How an Explanation System might work where questions like how or why are dealt with. Inference Rules use an if-statement and a then-statement. This gives Expert Systems the ability to find solutions to prescriptive and diagnostic problems. For instance:

If make of car includes high performance and you want Italian style then car you want is probably a Maserati Quattro Porte a rules base is made up of many such inference rules and inference engine uses these to draw its conclusions.