The first Huawei Lab Workshop of 2021 will be held  from the 14th to 16th of June (mornings in Edinburgh, late afternoon China)   The Huawei lab June workshop is the forum for researchers to share findings from their Huawei-sponsored research project through discussion, posters and reports. Attendees will have the opportunity to hear […]

Abstract String diagrams are becoming the established mathematical language of diagrammatic reasoning, with the mantra of ‘only connectivity matters’: equal terms are represented as isomorphic (or isotopic) diagrams. Unfortunately, when adding more structure to categories in the form of additional axioms, this mantra is lost: we must now consider diagrams up to rewriting. To perform […]

Time: 2021-02-11 09:30-10:30 ((UTC00:00) Edinburgh Video of the talk: https://youtu.be/sMWOQNfYIUw Speaker: James Wood, Strathclyde U Abstract: The metatheory of simple type systems presented using de Bruijn indices is well understood. We know to follow the principle that variable binding is the only interaction between the context and typing rules other than the variable rule. From […]

Jesse Sigal, University of Edinburgh. Automatic differentiation (AD) is an important family of algorithms which enables derivative based optimization. We show that AD can be simply implemented with effects and handlers by doing so in the Frank language. By considering how our implementation behaves in Frank’s operational semantics, we show how our code performs the […]

Technical Talk: Syntactic reasoning for digital circuits using graphs Dan R. Ghica When: Thursday, November 19, 10am (Edinburgh) Abstract: I will present a general diagrammatic theory of digital circuits, based on connections between monoidal categories and graph rewriting. The main achievement of the paper is conceptual, filling a foundational gap in reasoning syntactically and symbolically […]

Programming language Virtual Machines (VMs) must make many assumptions about how programs typically operate in order to effectively optimise them. We less commonly consider the many assumptions that VM developers and researchers hold about how VMs operate and the context within which they operate. In this talk, I will present a number of partly, or […]

by Dan R. Ghica We propose a core calculus for programming languages with effects, interpreted using a hypergraph-rewriting abstract machine. The intrinsic calculus syntax and semantics only deals with the basic structural aspects of programming languages: variables, names, and thunks. Everything else, including function abstraction and application, must be provided as extrinsic operations with associated […]

by Mario Alvarez Picallo When you hear the word ‘derivative’, differential calculus immediately comes to mind. This is, however, far from the only place where one can find them! Many ad-hoc notions of derivative have popped up over the years, in fields as disparate as incremental computation and digital circuits. In this talk we introduce […]

by Dan R. Ghica The interaction between (pure) computation and the physical world happens in two ways. The computation may act upon the world, which is usually called an effect, which is managed using the well known mechanism of monads in the type system of the programming language. But the computation may also require a resource, which is by symmetry called a co-effect, […]

On June 16 we had the pleasure of a technical talk by Prof. Michele Pagani, Institut de Recherche en Informatique Fondamentale, Université de Paris. Abstract: Backpropagation is a classic automatic differentiation algorithm computing the gradient of functions specified by a certain class of simple, first-order programs, called computational graphs.  It is a fundamental tool in […]