Laura K. Dillon

Learn More
This article describes a graphical interval logic that is the foundation of a tool set supporting formal specification and verification of concurrent software systems. Experience has shown that most software engineers find standard temporal logics difficult to understand and use. The objective of this article is to enable software engineers to specify and(More)
The constrained expression approach to analysis of concurrent software systems has several attractive features, including the facts that it can be used with a variety of design and programming languages and that it does not require a complete enumeration of the set of reachable states of the concurrent system. This paper reports on the construction of a(More)
Concurrent real-time systems are among the most difficult systems to design because of the many possible interleavings of events and because of the timing requirements that must be satisfied. We have developed a graphical environment based on Real-Time Graphical Interval Logic (RTGIL) for specifying and reasoning about the designs of concurrent real-time(More)
We present an interval logic, called Future Interval Logic (FIL), for the speciication and veriica-tion of concurrent systems. Interval logics allow reasoning to be carried out at the level of time intervals, rather than instants. However, unlike some other interval logics, the primitive objects in our semantic model for FIL are not intervals, but instants.(More)
Pharos is a .sca&zble distributed architecture for locating heterogeneous informatdon sources. !7he system incorporates a hierarcfiical metaduta structure into a multi-level rettieval system. Queries are resolved through an iterative decisionmaking process. The first step retrieves coarse-grain metadata, about all sources, stored on iocal, mastively(More)
Verifying that test executions are correct is a crucial step in the testing process. Unfortunately, it can be a very arduous and error-prone step, especially when testing a concurrent system. System developers can therefore benefit from oracles automating the verification of test executions.This paper examines the use of Graphical Interval Logic (GIL) for(More)
A method is presented for using symbolic execution to generate the verification conditions required for proving correctness of programs written in a tasking subset of Ada. The symbolic execution rules are derived from proof systems that allow tasks to be verified independently in local proofs, which are then checked for cooperation. The isolation nature of(More)
In a companion paper, we presented an interval logic, and showed that it is elementarily decidable. In this paper we extend the logic to allow reasoning about real-time properties of concurrent systems; we call this logic Real-Time Future Interval Logic (RTFIL). We model time by the real numbers, and allow our syntax to state the bounds on the duration of(More)
This paper explores an approach to design for verification in systems built atop a middleware framework which separates synchronization concerns from the “core-functional logic” of a program. The framework is based on a language-independent compositional model of synchronization contracts, called Szumo, which integrates well with popular OO design artifacts(More)