# Ivan di Liberti: Lindström in fabula

**Time: **
Wed 2023-03-22 10.00 - 12.00

**Location: **
Albano house 1, floor 3, Room U (Kovalevsky)

**Participating: **
Ivan di Liberti, Stockholm University

### Abstract

Lindström-type theorems are a paradigm of theorems that characterise fragments of logic among other logical system by identifying pivotal properties. The original theorem due to Lindström identifies first order logic as the minimal logic enjoying both compactness and Löwenheim-Skolem theorem. After an historical overview of Lindström-type theorems, we will see its incarnation in the 2-category of topoi, where Lindström theorem emerges tautologically as the very definition of coherent logic. Time permitting, we shall comment on Pitts’ approach to Craig interpolation theorem and its relevance in this story.