Objects (category theory)

Subobject

In category theory, a branch of mathematics, a subobject is, roughly speaking, an object that sits inside another object in the same category. The notion is a generalization of concepts such as subsets from set theory, subgroups from group theory, and subspaces from topology. Since the detailed structure of objects is immaterial in category theory, the definition of subobject relies on a morphism that describes how one object sits inside another, rather than relying on the use of elements. The dual concept to a subobject is a quotient object. This generalizes concepts such as quotient sets, quotient groups, quotient spaces, quotient graphs, etc. (Wikipedia).

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What is an Injective Function? Definition and Explanation

An explanation to help understand what it means for a function to be injective, also known as one-to-one. The definition of an injection leads us to some important properties of injective functions! Subscribe to see more new math videos! Music: OcularNebula - The Lopez

From playlist Functions

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Definition of a Surjective Function and a Function that is NOT Surjective

We define what it means for a function to be surjective and explain the intuition behind the definition. We then do an example where we show a function is not surjective. Surjective functions are also called onto functions. Useful Math Supplies https://amzn.to/3Y5TGcv My Recording Gear ht

From playlist Injective, Surjective, and Bijective Functions

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Definition of an Injective Function and Sample Proof

We define what it means for a function to be injective and do a simple proof where we show a specific function is injective. Injective functions are also called one-to-one functions. Useful Math Supplies https://amzn.to/3Y5TGcv My Recording Gear https://amzn.to/3BFvcxp (these are my affil

From playlist Injective, Surjective, and Bijective Functions

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The Definition of a Surjective(Onto) Function and Explanation

The Definition of a Surjective(Onto) Function and Explanation

From playlist Functions, Sets, and Relations

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Lecture 5: The definition of a topos (Part 2)

A topos is a Cartesian closed category with all finite limits and a subobject classifier. In his two seminar talks (of which this is the second) James Clift will explain all of these terms in detail. In his first talk he defined products, pullbacks, general limits, and exponentials and in

From playlist Topos theory seminar

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Lecture 4: The definition of a topos (Part 1)

A topos is a Cartesian closed category with all finite limits and a subobject classifier. In his two seminar talks (of which this is the first) James Clift will explain all of these terms in detail. In this talk he defines products, pullbacks, general limits, and exponentials and in Part 2

From playlist Topos theory seminar

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Topoi 2: The Subobject Classifier diagram

Topos, topoi, toposes. Previous video 1: https://youtu.be/Ysp7P4wW-zE This is the second video, discussing of the Subobject Classifier in a category of sets. For the followup video, just look at the videos uploaded one, two weeks later. The document used can be found here: https://gist.gi

From playlist Logic

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AlgTopReview: An informal introduction to abstract algebra

This is a review lecture on some aspects of abstract algebra useful for algebraic topology. It provides some background on fields, rings and vector spaces for those of you who have not studied these objects before, and perhaps gives an overview for those of you who have. Our treatment is

From playlist Algebraic Topology

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Eleftherios Pavlides & Thomas Banchoff - Hinge Elastegrities Shape Shifting - G4G12 April 2016

Named by analogy to tensegrity, maintaining form integrity through tension alone, hinge-elastegrity, maintaining form integrity with elastic hinges, is created by folding and weaving a shape-memory membrane, into a network of rigid members suspended with elastic hinges. The shape-shifting

From playlist G4G12 Videos

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Subtracting polynomials by using the addition method

👉 Learn how to subtract polynomials. To subtract polynomials, we first simplify the polynomials by removing all brackets. Then, we combine like terms. Like terms are terms that share the same base and power for each variable. When you have identified the like terms, we then apply the requ

From playlist How to subtract polynomials

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Subtracting two polynomials

👉 Learn how to subtract polynomials. To subtract polynomials, we first simplify the polynomials by removing all brackets. Then, we combine like terms. Like terms are terms that share the same base and power for each variable. When you have identified the like terms, we then apply the requ

From playlist How to subtract polynomials

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Subtracting two polynomials

👉 Learn how to subtract polynomials. To subtract polynomials, we first simplify the polynomials by removing all brackets. Then, we combine like terms. Like terms are terms that share the same base and power for each variable. When you have identified the like terms, we then apply the requ

From playlist How to subtract polynomials

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Subtracting linear functions to find domain

👉 Learn how to add or subtract two functions. Given two functions, say f(x) and g(x), to add (f+g)(x) or f(x) + g(x) or to subtract (f - g)(x) or f(x) - g(x) the two functions we use the method of adding/subtracting algebraic expressions together. To add or subtract two linear functions, w

From playlist Add and Subtract Functions

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Lecture 11: Sheaves form a topos (Part 2)

In this talk Patrick Elliott proves that the category of sheaves on a site is a topos, by discussing the exponentials and subobject classifier in detail. The notes are already online: The lecture notes are available here: http://therisingsea.org/notes/ch2018-lecture11.pdf. For the genera

From playlist Topos theory seminar

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Lecture 13: Higher-order logic and topoi (Part 3)

In this talk James Clift explains how to think about quantifiers in the context of topoi using adjunctions, and more generally how to extract a type theory out of a topos. This provides the means to "cut out" subobjects using formulas, which is in turn the fundamental idea to defining clas

From playlist Topos theory seminar

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Intro to Subsequences | Real Analysis

What are subsequences in real analysis? In today's lesson we'll define subsequences, and see examples and nonexamples of subsequences. We can learn a lot about a sequence by studying its subsequence, so let's talk about it! If (a_n) is a sequence, we can denote a subsequence of (a_n) as (

From playlist Real Analysis

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The Composition of Surjective(Onto) Functions is Surjective Proof

Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys The Composition of Surjective(Onto) Functions is Surjective Proof. I included some pictures in the proof with the hope that perhaps it makes more sense.

From playlist Proofs

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Topoi 1: Predicates vs. subsets

Topos, topoi, toposes. This is the warmup video for the discussion of the Subobject Classifier in a category of sets, in the next video. The document used can be found here: https://gist.github.com/Nikolaj-K/469b9ca1c085ea4ac4e3d7d0008913f5 Typo: In minute 42, the membership relation on sh

From playlist Logic

Related pages

Category of sets | Set theory | Quotient set | Topology | Codomain | Lattice (order) | Quotient space (topology) | Quotient graph | Categories for the Working Mathematician | Quotient group | Subquotient | Subterminal object | Equivalence class | Mathematics | Set (mathematics) | Group theory | Dual (category theory) | Category theory | Category (mathematics) | Subset | Morphism | Monomorphism | Equivalence relation | Subgroup | Category of groups | Epimorphism | Subobject classifier | Image (mathematics)