Last Monday should have been particularly jarring given the recent excitement. However, it was anything but. Sunlight was flooding the back garden and all the small birds of the neighborhood came together to perform an impromptu concert at maximum volume. I could hear them clearly through the double glazing. Spring had sprung in Dublin. And I’d just come back from Malta talking…

Experts in law and cryptography are speaking today at a smart contracts day in Athens, organised by IOHK chief scientist Aggelos Kiayias, chair of cyber security and privacy at the University of Edinburgh as well as director of its Blockchain Technology Laboratory. Smart contracts are an emerging technology that run on the same infrastructure that supports Bitcoin: a blockchain…

Experts in law and cryptography are speaking today at a smart contracts day in Athens, organised by IOHK chief scientist Aggelos Kiayias, chair of cyber security and privacy at the University of Edinburgh as well as director of its Blockchain Technology Laboratory. Smart contracts are an emerging technology that run on the same infrastructure that supports Bitcoin: a blockchain…

In my last blog post, we looked at the very basics of proof refinement systems. I noted at the end that there was a big drawback of the systems as shown, namely that information flows only in one direction: from the root of a proof tree to the leaves. In this post, we'll see how to get information to flow in the opposite direction as well. The code for this blog post can be…

In this blog post, I'm going to discuss the overall structure of a proof refinement system. Such systems can be used for implementing automatic theorem provers, proof assistants, and type checkers for programming languages. The proof refinement literature is either old or hard to understand, so this post, and subsequent ones on the same topic, will present it in a more casual…