In type theory, containers are abstractions which permit various "collection types", such as lists and trees, to be represented in a uniform way. A (unary) container is defined by a type of shapes S and a type family of positions P, indexed by S. The extension of a container is a family of dependent pairs consisting of a shape (of type S) and a function from positions of that shape to the element type. Containers can be seen as canonical forms for collection types. For lists, the shape type is the natural numbers (including zero). The corresponding position types are the types of natural numbers less than the shape, for each shape. For trees, the shape type is the type of trees of units (that is, trees with no information in them, just structure). The corresponding position types are isomorphic to the types of valid paths from the root to particular nodes on the shape, for each shape. Note that the natural numbers are isomorphic to lists of units. In general the shape type will always be isomorphic to the original non-generic container type family (list, tree etc.) applied to unit. One of the main motivations for introducing the notion of containers is to support generic programming in a dependently typed setting. (Wikipedia).
Category Theory 4.1: Terminal and initial objects
Terminal and initial objects
From playlist Category Theory
Anders Mörtberg: Yet Another Cartesian Cubical Type Theory yacctt
The lecture was held within the framework of the Hausdorff Trimester Program: Types, Sets and Constructions. Abstract: I will discuss recent work on developing a Cartesian cubical type theory inspired by the computational semantics of Computational Higher Type Theory of Angiuli et. al. Th
From playlist Workshop: "Types, Homotopy, Type theory, and Verification"
Lesson 02_03 Abstract and concrete types
Download the notebook files as they are added at: http://www.juanklopper.com/computer-programming/ All types are either concrete (that is a type right at the bottom of the tree of types) or abstract (basically everything higher up the tree). Concrete types are what we work with. We can c
From playlist The Julia Computer Language
Type Systems - Vladimir Voevodsky
Vladimir Voevodsky Institute for Advanced Study November 21, 2012
From playlist Mathematics
On the Setoid Model of Type Theory - Erik Palmgren
Erik Palmgren University of Stockholm October 18, 2012 For more videos, visit http://video.ias.edu
From playlist Mathematics
Category Theory 3.1: Examples of categories, orders, monoids
Examples of categories, orders, monoids.
From playlist Category Theory
Monica Nevins: Representations of p-adic groups via their restrictions to compact open subgroups
SMRI Algebra and Geometry Online 'Characters and types: the personality of a representation of a p-adic group, revealed by branching to its compact open subgroups' Monica Nevins (University of Ottawa) Abstract: The theory of complex representations of p-adic groups can feel very technical
From playlist SMRI Algebra and Geometry Online
This is part of a series of lectures on the Zermelo-Fraenkel axioms for set theory. We discuss the axiom of infinity, and give some examples of models where it does not hold. For the other lectures in the course see https://www.youtube.com/playlist?list=PL8yHsr3EFj52EKVgPi-p50fRP2_SbG
From playlist Zermelo Fraenkel axioms
Defining Numbers & Functions Using SET THEORY // Foundations of Mathematics
We are all familiar with numbers and functions....but are these the most basic, most foundational concept in mathematics? Mathematicians use set theory as the basic building blocks of so much of math. In this video we are going to see how we can think of numbers and functions in terms of s
From playlist Cool Math Series
On PC-exact saturation - I. Kaplan - Workshop 3 - CEB T1 2018
Itay Kaplan (Hebrew University, Jerusalem) / 30.03.2018 On PC-exact saturation (joint work with Nick Ramsey and Saharon Shelah) A theory T is said to have exact saturation at a (usually singular) cardinal κ if there is a model which is κ- saturated but not κ +- saturated. T has PC-exact
From playlist 2018 - T1 - Model Theory, Combinatorics and Valued fields
The abstract chromatic number - Leonardo Nagami Coregliano
Computer Science/Discrete Mathematics Seminar I Topic: The abstract chromatic number Speaker: Leonardo Nagami Coregliano Affiliation: University of Chicago Date: March 22, 2021 For more video please visit http://video.ias.edu
From playlist Mathematics
ω+1 and 1,008,906: my MegaFavNumbers (Part 1 of 2)
I only talk about omega plus one in this video xD Another one is on the way! Playlist of #MegaFavNumbers https://www.youtube.com/playlist?list=PLar4u0v66vIodqt3KSZPsYyuULD5meoAo For first-time set theorists, I highly recommend Naive Set Theory by Paul Halmos: https://www.amazon.com/Naive
From playlist MegaFavNumbers
Lecture 9: Higher-order logic and topoi (Part 2)
Most of this talk was spent defining a higher-order logic, which Lambek and Scott call a "type theory". At the end it was explained how to organise certain terms of such a logic into a category, which next time we will prove is a topos. The lecture notes are available here: http://theris
From playlist Topos theory seminar
SUSY for Strings and Branes, Part 3 - Melanie Becker
SUSY for Strings and Branes, Part 3 Melanie Becker Texas A&M University July 22, 2010
From playlist PiTP 2010
Bas Spitters: Modal Dependent Type Theory and the Cubical Model
The lecture was held within the framework of the Hausdorff Trimester Program: Types, Sets and Constructions. Abstract: In recent years we have seen several new models of dependent type theory extended with some form of modal necessity operator, including nominal type theory, guarded and c
From playlist Workshop: "Types, Homotopy, Type theory, and Verification"