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Effective Categorical Reasoning


Bob Coecke

Suitable for

MSc in Computer Science


Category theory is an important tool in theoretical computer science. In introductory courses proofs are generally conducted by pasting commuting diagrams together, or simple equational reasoning. There are further proof styles in category theory, for example using string diagrams, “Yoneda style” proofs and the use of internal logics. The aim of this project would be to investigate and contrast these different approaches, showing how, and when, they can be used effectively, on realistic problems. A concrete starting point would be to understanding the techniques involved, and then apply them to non trivial proofs from the literature in order to demonstrate their relative benefits. An ideal outcome would be an example based account for computer scientists of how to reason efficiently in category theory.

Prerequisites: A good understanding of elementary category theory and comfort with mathematical proofs is essential. Some experience with string diagrams, as for example in the quantum computer science courses in the department would also be helpful.