On a generalization of variable precision logic

Variable-precision logic was introduced by R.S. Michalski and P.H. Winston (Artif. Intell., vol.29, p.121-46, 1986) as a means for representing reasoning in the face of exceptions. Using the framework of belief structures, some of their ideas are extended. In particular, a general framework that easily allows the representation of different types of rules in a unified manner is provided. This approach also allows for a lack of specificity in the associated qualifying probabilities