# Category Archives: Uncategorized

## Type theoretic replacement & the n-truncation

This post is to announce a new article that I recently uploaded to the arxiv: https://arxiv.org/abs/1701.07538 The main result of that article is a type theoretic replacement construction in a univalent universe that is closed under pushouts. Recall that in … Continue reading

## HoTT MRC

From June 4 — 10, 2017, there will be a workshop on homotopy type theory as one of the AMS’s Mathematical Research Communities (MRCs).

## HoTT is not an interpretation of MLTT into abstract homotopy theory

Almost at the top of the HoTT website are the words: “Homotopy Type Theory refers to a new interpretation of Martin-Löf’s system of intensional, constructive type theory into abstract homotopy theory. ” I think it is time to change these words … Continue reading

## The HoTT Book does not define HoTT

The intent of this post is to address certain misconceptions that I’ve noticed regarding the HoTT Book and its role in relation to HoTT. (At least, I consider them misconceptions.) Overall, I think the HoTT Book project has been successful … Continue reading

## The cumulative hierarchy of sets (guest post by Jeremy Ledent)

In section 10.5 of the HoTT book, the cumulative hierarchy V is defined as a rather non-standard higher inductive type. We can then define a membership relation ∈ on this type, such that (V, ∈) satisfies most of the axioms … Continue reading

## Homotopical Patch Theory

This week at ICFP, Carlo will talk about our paper: Homotopical Patch Theory Carlo Angiuli, Ed Morehouse, Dan Licata, Robert Harper Homotopy type theory is an extension of Martin-Loef type theory, based on a correspondence with homotopy theory and higher category … Continue reading

## Homotopy Theory in Homotopy Type Theory: Introduction

Many of us working on homotopy type theory believe that it will be a better framework for doing math, and in particular computer-checked math, than set theory or classical higher-order logic or non-univalent type theory. One reason we believe this … Continue reading