3 papers
math.CT2026
The points of canonical extensions of doctrines
Sam van Gool, Joshua L. Wrigley
We analyse the space of points of the canonical extension of a coherent doctrine. We first give a full characterisation of doctrine morphisms that are extensible, and relate it to…
math.LO2026
Uniform Interpolation
Sam van Gool
Uniform interpolation is a strengthening of interpolation that holds for certain propositional logics. The starting point of this chapter is a theorem of A. Pitts, which shows that…
cs.LO2024
Mechanised uniform interpolation for modal logics K, GL, and iSL
Hugo Férée, Iris van der Giessen, Sam van Gool +1
The uniform interpolation property in a given logic can be understood as the definability of propositional quantifiers. We mechanise the computation of these quantifiers and prove…