# Monthly Archives: May 2017

## Postcard from Cornwall

A photo taken along the South West Coast Path, as it runs to St Anthony Head in Cornwall. It’s a particularly beautiful stretch of the path, and a quick ferry ride takes us across the bay from the apartment we rent this time of … Continue reading

## Gerhard Gentzen’s Shorthand Notes

Springer have just published an exceptional volume that should quite certainly be in any university library that has any kind of logic collection. From the blurb of Saved from The Cellar – Gerhard Gentzen’s Shorthand Notes on Logic and Foundations of Mathematics: “Attempts … Continue reading

## Maddy on sets, categories, and the multiverse

Here are three large-scale issues. First, in what good sense or senses, if any, does ZFC provide a foundation for mathematics. Second, can category theory provide an alternative(?), or better(?) foundation for some or all mathematics? Third, should set theory … Continue reading

Posted in This and that | 2 Comments

## Empty domains #3 – from Vej Kse

The following was posted as a comment to Empty domains #1 by Vej Kse — but I think it is particularly interesting and worth highlighting as a stand-alone post.  There is an elegant and natural (from a user’s perspective) way to allow … Continue reading

Posted in This and that | 7 Comments

## Empty domains #2

Here is a long quotation from Oliver and Smiley in their Plural Logic, motivating their adoption of a universally free logic (i.e. one allowing empty domains and empty terms). If empty singular terms are outlawed, we are deprived of logic as a tool … Continue reading

Posted in This and that | 6 Comments

## Empty domains #1

From wild mathematical universes back to nothing much at all: the question of empty domains in first-order logic. Not that I have anything very insightful to say:  but I want to get my mind clearer before committing myself to a … Continue reading

Posted in IFL, Logic | 10 Comments

## New foundations?

This I find intriguing: Can we actually use [homotopy] type theory as the foundation for mathematics? That is, must we consider the objects of mathematics to “really” be built out of sets, with “types” just a convenient fiction for talking … Continue reading

Posted in This and that | 5 Comments