A picture of me, with the Forth Bridge in the background

A picture of me, with the Forth Bridge in the background

Hello! Iā€™m George, a PhD student researcher at the University of Birmingham, under the supervision of Dan Ghica and Miriam Backens. I am a member of the University of Birmingham Theory Group, and helped run the weekly seminar from March 2022 to March 2024.

I also used to work part time at the Huawei Edinburgh Programming Languages Lab.

About me

My primary research interests are in graphical calculi for compositional systems and the lambda calculus using monoidal categories, and reasoning about these structures diagrammatically using string diagrams.

I am currently writing up my PhD thesis on a fully compositional theory of sequential digital circuits with delay and feedback. This project is based on work by Ghica and Jung who modelled digital circuits as morphisms in a symmetric traced monoidal category. My job was to tidy this all up and make it formal, leading to three sound and complete semantics for sequential circuits: a denotational semantics of monotone stream functions, a reductions-based operational semantics, and an algebraic semantics. Using recent work on string diagram graph rewriting, this gives us a framework suitable for performing graph rewriting on digital circuits.

When I'm not researching, I play the piano and go on adventures usually involving trains, canals or both. I occasionally take photos of pretty things and put them on Instagram. If you want something less pretty, here are some pictures of me!

You might want to read my CV.

Contact me


If you find a mistake, make an issue and I'll try to sort it out. Alternatively, you can figure out how my static site generator works and fix it yourself with a pull request!


I like doing little coding projects: here are some of them:

I've made some guides to impart the admin knowledge I've gained from four years of doing things in the Birmingham theory group to help the next generation:

Douvk webring

Get to know other PhD students from my Birmingham days.

ā† Bruno da Rocha Paiva ā€¢ Jon Freer ā†’