Sarah Grebing

The KeY Platform for Verification and Analysis of Java Programs

The KeY system offers a platform of software analysis tools for sequential Java. Foremost, this includes full functional verification against contracts written in the Java Modeling Language. But the approach is general enough to provide a basis for other methods and purposes: (i) complementary validation techniques to formal verification such as testing and debugging, (ii) methods that reduce the complexity of verification such as modularization and abstract interpretation, (iii) analyses of non-functional properties such as information flow security, and (iv) sound program transformation and code generation. We show that deductive technology that has been developed for full functional verification can be used as a basis and framework for other purposes than pure functional verification. We use the current release of the KeY system as an example to explain and prove this claim.

A Usability Evaluation of Interactive Theorem Provers Using Focus Groups

The effectiveness of interactive theorem provers (ITPs) increased such that the bottleneck in the proof process shifted from effectiveness to efficiency. While in principle large theorems are provable, it takes much effort for the user to interact with the system. A major obstacle for the user is to understand the proof state in order to guide the prover in successfully finding a proof. We conducted two focus groups to evaluate the usability of ITPs. We wanted to evaluate the impact of the gap between the user’s model of the proof and the actual proof performed by the provers’ strategies. In addition, our goals are to explore which mechanisms already exist and to develop, based on the existing mechanisms, new mechanisms that help the user in bridging this gap.

An Interaction Concept for Program Verification Systems with Explicit Proof Object

Deductive program verification is a difficult task: in general, user guidance is required to control the proof search and construction. Providing the right guiding information is challenging for users and usually requires several reiterations. Supporting the user in this process can considerably reduce the effort of program verification.