### Boole’s Rings

- Consistency strength lower bounds for the proper forcing axiom via the core model induction March 5, 2020 Sandra Müller
- Logic Colloquium Poznan - TBA March 5, 2020 Sandra Müller
- North American Annual Meeting of the ASL - How to obtain lower bounds in set theory March 4, 2020 Sandra Müller
- International Day of Mathematics, Vienna - Das Unbegreifliche verstehen - die Faszination Unendlichkeit March 3, 2020 Sandra Müller
- The real numbers are not interpretable in the complex field February 24, 2020 Joel David Hamkins

### Comments on Boole’s Rings

- Comment on Math for eight-year-olds: graph theory for kids! by graph theory for children - Oxford Blog March 28, 2020 Comments for Joel David Hamkins
- Comment on Math for seven-year-olds: graph coloring, chromatic numbers, and Eulerian paths and circuits by graph theory for children - Oxford Blog March 28, 2020 Comments for Joel David Hamkins
- Comment on Math for kids: fun with orthoprojections! by Marco March 27, 2020 Comments for Joel David Hamkins
- Comment on Set-theoretic geology by A tutorial in set-theoretic geology, London 2011 | Joel David Hamkins March 21, 2020 Comments for Joel David Hamkins
- Comment on The real numbers are not interpretable in the complex field by Joel David Hamkins March 4, 2020 Comments for Joel David Hamkins

# Author Archives: Carl Mummert

## Talk: Survey of mathematically applied computability theory

Despite being relatively small, my department has three faculty in finite combinatorics, in addition to having me in logic. I recently gave a series of two talks in our seminar to present a broad overview of classical computability theory, and … Continue reading

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## 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

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## An example with Dedekind cuts

In this post, I will briefly describe an example in computability theory that is well known, but not easy to find in the literature. It gives one reason why Dedekind cuts are difficult to work with computationally. Theorem. There is … Continue reading

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## Talk on Reverse Mathematics and Ramsey Theory

This is a copy of my notes from a two-hour talk I gave at our local combinatorics seminar about Reverse Mathematics and Ramsey Theory. The audience consisted of our combinatorialists, who are not logicians, and so the talk is intended … Continue reading

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## Talk on the existence of connected components of graphs

This week I am attending a seminar at Dagstuhl on Measuring the Complexity of Computational Content: Weihrauch Reducibility and Reverse Analysis. This post has slides from my talk and some blog-only remarks to expand on them.

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## Filter quantifiers

I have been supervising an undergraduate student in an independent study in topology this semester. We have just finished the Stone–Čech compactification, and the semester is ending, so I want to end with an ultrafilter based proof of Hindman’s theorem. … Continue reading

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## Talk on Reverse Mathematics and the Modal Logic of Reverse Mathematics

This is a transcription of notes from a talk I gave on November 1, 2013 to the interdisciplinary logic seminar at the University of Connecticut. I gave a general introduction to Reverse Mathematics and then spoke about my work with … Continue reading

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## Internal combinatorics and uniform reducibility

This post is a set of notes from a talk I gave on December 5th for the discrete mathematics seminar at Marshall University. I want to argue that logical analysis can reveal the “internal combinatorics” of theorems, using some recent … Continue reading

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## Quiz on public peer review

I have been required to complete a “responsible conduct of research” training module by the research office at my school. The reason I am commenting is that I was asked to answer the following question “true” or “false”. This is … Continue reading

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## Computable roots of computable functions

Here are several interesting results from computable analysis: Theorem 1. If $f$ is a computable function from $\mathbb{R}$ to $\mathbb{R}$ and $\alpha$ is an isolated root of $f$, then $\alpha$ is computable. Corollary 2. If $p(x)$ is a polynomial over … Continue reading