Elements of Variable Precision Logic Based on Art 870113
Variable precision logic (VPL) is a formalism for reasoning with uncertain information, in situations where resources constrain the amount of Reasoning which can take place. The conclusions developed using VPL may vary in certainty according to the computational resources that are made available.  Thus, VPL appears to have many potential applications, in areas such as diagnosis, classification, real-time control, etc.
This paper describes implementation methods for erabedding certain elements of VPL on top of ART, the Automated Reasoning Tool expert systems language developed by Inference Corporation.  ART provides a variety of flexible constructs for expert systems programming, so that alternative systems for managing uncertainty can be implemented on top of ART. The elements of VPL discussed in this paper include certainties of facts and rules, censored rules, and time resource constraints on logical derivations.