Schematic Kleene algebra with tests (SKAT) supports the equational verification of flowchart scheme equivalence and captures simple while-programs with assignment statements. We formalise SKAT in Isabelle/HOL, using the quotient type package to reason equationally in this algebra. We apply this formalisation to a complex flowchart transformation proof from the literature. We extend SKAT with as...

This tool paper describes Leap, a tool for the verification of concurrent datatypes and parametrized systems composed by an unbounded number of threads that manipulate infinite data. Leap receives as input a concurrent program description and a specification and automatically generates a finite set of verification conditions which are then discharged to specialized decision procedures. The vali...

We present Why3, a tool for deductive program verification, and WhyML, its programming and specification language. WhyML is a first-order language with polymorphic types, pattern matching, and inductive predicates. Programs can make use of record types with mutable fields, type invariants, and ghost code. Verification conditions are discharged by Why3 with the help of various existing automated...

In this paper, we discuss the challenges that have to be addressed when organising program verification competitions. Our focus is on competitions for verification systems where the participants both formalise an informally stated requirement and (typically) provide some guidance for the tool to show it. The paper draws its insights from our experiences with organising a program verification co...

Program transformation is a restricted form of software construction that can be amenable to formal verification. When successful, the nature of the evidence provided by such a verification is considered strong and can constitute a major component of an argument that a high-consequence or safety-critical system meets its dependability requirements. This article explores the application of novel...

Schematic Kleene algebra with tests (SKAT) supports the equational verification of flowchart scheme equivalence and captures simple while programs with assignment statements. We formalise SKAT in Isabelle/HOL, using the quotient type package to reason equationally in this algebra. We apply this formalisation to a complex flowchart transformation proof from the literature. We extend SKAT with as...

Design patterns and frameworks as reuse mechanisms hold much promise in the continuing effort to manage software complexity. They provide a vehicle for experts to convey their experience to other software designers. The formal verification of programs is an aspect of system development which software designers find difficult and cumbersome. This is mainly due to the complexity and amount of wor...

When a technology reaches a higher level of maturity, its development begins to diversify and to differentiate. In 1885 engineers were happy to build the first car powered by a gasoline engine. Today we see a whole spectrum of vehicles ranging from city cars, limousines, off-road vehicles, sports cars, buses, trucks, etc., that share some basic technologies but greatly differ in details. Softwa...

Verification of functional correctness of control programs is an essential task for the development of space electronics; it is difficult and time-consuming and typically outweighs design and programming tasks in terms of development hours. We present a verification approach designed to help spacecraft engineers reduce the effort required for formal verification of low-level control programs ex...

The Eiffel method and language integrate a number of ideas originating from work on program verification. This position paper describes the goals of the Eiffel approach, presents current Eiffel-based verification techniques using contracts for run-time checks for testing and debugging, and outlines ongoing work on static verification.