### Boole’s Rings

- The modal logic of potentialism, ILLC Amsterdam, May 2019 April 15, 2019 Joel David Hamkins
- Is there just one mathematical universe? DRIFT, Amsterdam, May 2019 April 14, 2019 Joel David Hamkins
- Philosophy of Mathematics, graduate lecture seminar, Oxford, Trinity term 2019 April 11, 2019 Joel David Hamkins
- Kelley-Morse set theory does not prove the class Fodor principle April 9, 2019 Joel David Hamkins
- A Rodgers-Saxl type conjecture for characters April 5, 2019 Nick Gill

### Comments on Boole’s Rings

- Comment on Is there just one mathematical universe? DRIFT, Amsterdam, May 2019 by Hendrik Boom April 14, 2019 Comments for Joel David Hamkins
- Comment on Kelley-Morse set theory does not prove the class Fodor Principle, CUNY Set Theory Seminar, March, 2019 by Joel David Hamkins March 22, 2019 Comments for Joel David Hamkins
- Comment on An inconsistent form of club guessing by saf March 13, 2019 Comments for Assaf Rinot
- Comment on An inconsistent form of club guessing by Ari B. March 10, 2019 Comments for Assaf Rinot
- Comment on Draw an infinite chessboard in perspective, using straightedge only by Joel David Hamkins February 25, 2019 Comments for Joel David Hamkins

# Category Archives: Papers

## Reverse Mathematics of Matroids

This post is about the paper Reverse Mathematics of Matroids by Jeff Hirst and me. We look at basis theorems for countable vector spaces, countable graphs, and countable enumerated matroids. These three kinds of structures turn out to be extremely … Continue reading

Posted in Papers, Research
Leave a comment

## An incompleteness theorem for β_{n} models

My first paper was “An incompleteness theorem for $\beta_n$ models” with Stephen Simpson [1]. It’s a short paper, but the idea is very pretty. We know that the incompleteness theorem implies there are strange models of arithmetic, but these models … Continue reading

Posted in Papers, Research
2 Comments