Type-driven Verification of Communicating Systems

Dr Edwin Brady, University of St Andrews

Idris (http://idris-lang.org/) is a general-purpose programming language with an expressive type system which allows a programmer to state properties of a program precisely in its type. Type checking is equivalent to formally and mechanically checking a program's correctness. Introductory examples of programs verified in this way typically involve length preserving operations on lists, or ordering invariants on sorting.

Realistically, though, programming is not so simple: programs interact with users, communicate over networks, manipulate state, deal with erroneous input, and so on. In this talk I will give an introduction to programming in Idris, with demonstrations, and show how its advanced type systems allows us to express such interactions precisely. I will show how it supports verification of stateful and communicating systems, in particular giving an example showing how to verify properties of concurrent communicating systems.