Další seminář z algebry se koná 7.5.2020 od 13.00 online na platformě ZOOM. Informace pro připojení a další program semináře je zde.

Christian Espindola

Topos-theoretic completeness theorems

Abstrakt:
In this talk we will delve into the background details of the previous talk by introducing syntactic proof systems and their categorical semantics, including the construction of syntactic categories and $\kappa$-classifying toposes, as well as the role of certain properties of Grothendieck topologies and Kripke-Joyal semantics. We will then study some topos-theoretic completeness theorems for certain infinitary logics that generalize results of Deligne and Joyal.