Recently the following question came up in tutorial as I had a student looking at ordinal arithmetic. Basically, you want to show that if an ordinal is divisible on the right by 2 and by 3, then it...
Roy Shalev is finishing his doctorate working with Assaf Rinot at Bar Ilan University, and in this paper posted to ArXiv yesterday he answers a question left open by our work with Cummings and Moore...
Here is a stash of notes I prepared prior to my oral comprehensive exam at Michigan back in 1990 or so. They are based on a course taught by my advisor, Andreas Blass. These represent a young grad...
Today marks the end of teaching for Fall semester 2023. In my set theory course, I spent the day contextualizing some of the questions I put on their take-home final. One of the questions has them...
I am just trying out this blog as a space to disseminate some notes I've written up over the years. For example, this short one writes up an old result of Galvin and Shelah showing \(2^{\aleph_0}...
A revised version of our paper with James Cummings and Justin Moore on large minimal non-\(\sigma\)-scattered linear orderings is available and attached to this post. We have submitted to Advances in...
I am teaching a graduate-level introduction to set theory course this semester, and we got to spend some time with one of my favorite set-theory facts: the Continuum Hypothesis holds if and only if...
