Tag: 2019

  • Discussing “All (∞,1)-Toposes Have Strict Univalent Universes”

    Discussing “All (∞,1)-Toposes Have Strict Univalent Universes”

    I have written before about 2-category theory, where we have objects, arrows between objects, and arrows (sometimes called 2-cells) between those arrows. The canonical example are collections of categories, which have layers of categories; functors; and natural transformations. ∞-categories generalise this to an infinite stack of layers of n-cells. An (∞,1)-category is a special case…

  • Discussing “Proof Theory and Algebra in Logic”

    Discussing “Proof Theory and Algebra in Logic”

    I was pleased to see this book bubbling up through my recommendations, as I once saw a keynote talk by Hiroakira Ono at a logic conference in my former home city of Wellington and it was one of the most cogent and exciting logic talks I’ve ever enjoyed. Ono’s textbook is split into two parts,…