Set Theory and Topology seminar (BGU)
order theory, giving rise to the model theoretic notion of internality.
The collection of such interpretations has a geometric structure,
namely, the structure of a definable groupoid. The structure allows us
to reformulate problems about interpretations in terms of definable
An instance of this situation is provided Picard–Vessiot theory, and
more general Galois theory of differential equations. In these cases,
the formalism produces results on existence and uniqueness of
The talk will be related (but independent from) my talk on the
colloquium. I will explain all terminology.