Esther Elbaz (Paris)

Is o-minimality of the open-core an elementary property?

Let $M$ be a structure endowed with a dense linear order without endpoints. Its open-core is its reduced generated by the collection of all of its open definable sets (in any Cartesian power of $M$). We prove that the property of having an o-minimal open core isn't elementary. This is a joint work with Alexi Block-Gorman.