Carnegie Mellon University
Browse

Formal Verification by Symbolic Evaluation of Partially-Ordered Trajectories

Download (432.73 kB)
journal contribution
posted on 1987-01-01, 00:00 authored by Carl-Johan H. Seger, Randal E. Bryant
Symbolic trajectory evaluation provides a means to formally verify properties of a sequential system by a modified form of symbolic simulation. The desired system properties are expressed in a notation combining Boolean expressions and the temporal logic 'next-time' operator. In its simplest form, each property is expressed as an assertion [A⇒C], where the antecedent A expresses some assumed conditions on the system state over a bounded time period, and the consequent C expresses conditions that should result. A generalization allows simple invariants to be established and proven automatically. The verifier operates on system models in which the state space is ordered by 'information content'. By suitable restrictions to the specification notation, we guarantee that for every trajectory formula, there is a unique weakest state trajectory that satisfies it. Therefore, we can verify an assertion [A⇒C] by simulating the system over the weakest trajectory forA and testing adherence toC. Also, establishing invariants correspond to simple fixed point calculations. This paper presents the general theory underlying symbolic trajectory evaluation. It also illustrates the application of the theory to the taks of verifying switch-level circuits as well as more abstract implementations.

History

Publisher Statement

All Rights Reserved

Date

1987-01-01

Usage metrics

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC