Ivan Di Liberti (Göteborgs universitet) will give a talk on
Logics in the 2-category of topoi
Abstract:
Inspired by a recent characterisation of coherent topoi as a class of Kan injectives, we provide a tentative definition of fragment of geometric logic. Logics can be treated as mathematical objects, and one can study them from several points of view. Our main motivation is to reproduce Lindstrom-type characterisations of first order logic. We take the opportunity to discuss several aspects of Kan injectivity in the bicategory of topoi.