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 similar from the point of view of their dependence relations.

### Boole’s Rings

- The rearrangement number: how many rearrangements of a series suffice to verify absolute convergence? Mathematics Colloquium at Penn, September 2016 July 30, 2016 Joel David Hamkins
- Set-theoretic geology and the downward-directed grounds hypothesis, CUNY Set Theory seminar, September 2016 July 30, 2016 Joel David Hamkins
- Crecimiento en grupos y otras estructuras July 19, 2016 Nick Gill
- More notions of forcing add a Souslin tree July 17, 2016 Assaf Rinot
- In praise of some history July 9, 2016 Asaf Karagila

### Comments on Boole’s Rings

- Comment on Set-theoretic geology and the downward-directed grounds hypothesis, CUNY Set Theory seminar, September 2016 by Joel David Hamkins July 30, 2016 Comments for Joel David Hamkins
- Comment on Set-theoretic geology and the downward-directed grounds hypothesis, CUNY Set Theory seminar, September 2016 by Joel David Hamkins July 30, 2016 Comments for Joel David Hamkins
- Comment on Set-theoretic geology and the downward-directed grounds hypothesis, CUNY Set Theory seminar, September 2016 by allenknutson July 30, 2016 Comments for Joel David Hamkins
- Comment on The rearrangement number: how many rearrangements of a series suffice to verify absolute convergence? Mathematics Colloquium at Penn, September 2016 by Ali Sadegh Daghighi July 30, 2016 Comments for Joel David Hamkins
- Comment on Set-theoretic geology and the downward-directed grounds hypothesis, CUNY Set Theory seminar, September 2016 by John Baez July 30, 2016 Comments for Joel David Hamkins