Blog for CSE 471/598 Intro to AI Course
May be because in propositional logic, we considered everything independent. For example, in the example, John calling is not related to Mary calling..We were not able to express dependence there..
As mentioned in class, we didn't have the notion of degrees of belief in propositional logic. So, as mentioned by Srinath, if John called, our conclusion would be that the alarm went off. Nothing could diminish or amplify our belief in that. The clause A would be derived from that. If Mary called as well, nothing would change, since A would already have been derived. In Probabilistic Propositional Logic, however, having the two facts (Mary called, John called) would actually impact on the belief that A occurred.