Dan Marsden (University of Nottingham)

Games, Comonads and Compositionality

Note location change: Roger Stevens LT 13 (10.13)

Recent work of Abramsky, Dawar and Wang, and subsequently Abramsky and Shah, provided a categorical abstraction of model comparison games such as the Ehrenfeucht-Fraïssé, pebble and bisimulation games, in the form of so-called game comonads. This work opened up new connections between disciplines associated with computational power and complexity such as finite model theory and combinatorics, and areas traditionally focussed upon the structural understanding of computation and logic, such as program semantics.

This talk will introduce the comonadic perspective upon model comparison games. I shall then describe more recent work, jointly with Tomáš Jakl and Nihil Shah, giving a categorical account of Feferman-Vaught-Mostowski type theorems with this categorical framework.

The talk will aim to be reasonably self-contained, assuming only a basic background in logic, and some understanding of the categorical notions of category, functor and natural transformation.