This will be talk for the CUNY Set Theory seminar, Friday, March 22, 2019, 10 am in room 6417 at the CUNY Graduate Center.
Abstract. I shall discuss recent joint work with Victoria Gitman and Asaf Karagila, in which we proved that Kelley-Morse set theory (which includes the global choice principle) does not prove the class Fodor principle, the assertion that every regressive class function defined on a stationary class is constant on a stationary subclass. Indeed, it is relatively consistent with KM for any infinite with that there is a class function that is not constant on any stationary class. Strikingly, it is consistent with KM that there is a sequence of classes , each containing a class club, but the intersection of all is empty. Consequently, it is relatively consistent with KM that the class club filter is not -closed.
I am given to understand that the talk will be streamed live online. I’ll post further details when I have them.
I am given to understand that a live stream of the talk will be available at: https://videostreaming.gc.cuny.edu/videos/livestreams/page1/.