Time: Thursday, 29 April 2021, 9:30 Edinburgh time (UTC+1) Abstract: We’ll tour my Nominal techniques Haskell package, which provides easy access to types and type classes with nominal-style binding. Why do you need this?  Because it lets you program and reason on name-like data (e.g. variable symbols, pointers, links), and binding (e.g. name-binding, hiding, locality) at […]

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 […]

 A graphical language for closed monoidal categories, by Dan Ghica. Diagrams, schematics, blueprints and so on play an important role in engineering, architecture, construction, and other activities where projects need to be formally specified. In mathematics the role of diagrams has been, at least until recently, mostly that of illustrating concepts, rather than specifying formally […]

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 […]

On Tuesday 27th October at 1:15pm (UK time), Mario Alvarez-Picallo, The Difference Lambda Calculus Abstract: Cartesian difference categories are a recent generalisation of Cartesian differential categories which introduce a notion of “infinitesimal” arrows satisfying an analogue of the Kock-Lawvere axiom, with the axioms of a Cartesian differential category being satisfied only “up to an infinitesimal […]

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 […]