Using Answer Set Programming in the Development of Verified Software

Software forms a key component of many modern safety and security critical systems. One approach to achieving the required levels of assurance is to prove that the software is free from bugs and meets its specification. If a proof cannot be constructed it is important to identify the root cause as it may be a flaw in the specification or a bug. Novice users often find this process frustrating and discouraging, and it can be time-consuming for experienced users. The paper describes a commercial application based on Answer Set Programming called Riposte. It generates simple counter-examples for false and unprovable verification conditions (VCs). These help users to understand why problematic VC are false and makes the development of verified software easier and faster

Introduction to the 28th International Conference on Logic Programming Special Issue

We are proud to introduce this special issue of the Journal of Theory and Practice of Logic Programming (TPLP), dedicated to the full papers accepted for the 28th International Conference on Logic Programming (ICLP). The ICLP meetings started in Marseille in 1982 and since then constitute the main venue for presenting and discussing work in the area of logic programming

An Automatically Verified Prototype of the Tokeneer ID Station Specification

The Tokeneer project was an initiative set forth by the National Security Agency (NSA, USA) to be used as a demonstration that developing highly secure systems can be made by applying rigorous methods in a cost effective manner. Altran Praxis (UK) was selected by NSA to carry out the development of the Tokeneer ID Station. The company wrote a Z specification later implemented in the SPARK Ada programming language, which was verified using the SPARK Examiner toolset. In this paper, we show that the Z specification can be easily and naturally encoded in the {log} set constraint language, thus generating a functional prototype. Furthermore, we show that {log}'s automated proving capabilities can discharge all the proof obligations concerning state invariants as well as important security properties. As a consequence, the prototype can be regarded as correct with respect to the verified properties. This provides empirical evidence that Z users can use {log} to generate correct prototypes from their Z specifications. In turn, these prototypes enable or simplify some verificatio activities discussed in the paper