Finite Differencing of Logical Formulas for Static Analysis

This paper concerns mechanisms for maintaining the value of an instrumentation predicate (a.k.a. derived predicate or view), defined via a logical formula over core predicates, in response to changes in the values of the core predicates. It presents an algorithm for transforming the instrumentation predicate’s defining formula into a predicate-maintenance formula that captures what the instrumentation predicate’s new value should be.This technique applies to program-analysis problems in which the semantics of statements is expressed using logical formulas that describe changes to corepredicate values, and provides a way to reflect those changes in the values of the instrumentation predicates.