1.fire the rules
2.present the user with questions
3.add the answer to the ES "blackboard" (assertion base)
4.infer a new face from a rule
5.ass the inference fact to the backboard
6.match the blackboard to the rule
7.if there are any matches, fire rules
8.if there are two further matches, check to see if goal is reached
9.fire the lowest numbered unfired rule