The purpose of this paper is to present the logic-based approach to the problem of automatic verification of the different specifications of an information system. The data flow analysis method and its basic product, data flow diagrams (DFDs), are used as an example. A traditional approach to automated DFD verification is illustrated. In this approach, DFDs are represented by database logical files, and verification rules are implemented as data manipulation procedures. Next described is the logic-based approach. First, the DFD verification problem is conceptualized. Then it is described in terms of logic, as implemented in Prolog. A comparison of the two approaches is made by looking at respective implementations of a particular DFD verification policy. Advantages of the logic-based approach are discussed, and its usefulness for the automatic verification of other system descriptions, like data dictionary or conceptual data models is pointed out.