General topology | Closure operators

Closure (topology)

In topology, the closure of a subset S of points in a topological space consists of all points in S together with all limit points of S. The closure of S may equivalently be defined as the union of S and its boundary, and also as the intersection of all closed sets containing S. Intuitively, the closure can be thought of as all the points that are either in S or "near" S. A point which is in the closure of S is a point of closure of S. The notion of closure is in many ways dual to the notion of interior. (Wikipedia).

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What is a closed set ?

I define closed sets, an important notion in topology and analysis. It is defined in terms of limit points, and has a priori nothing to do with open sets. Yet I show the important result that a set is closed if and only if its complement is open. More topology videos can be found on my pla

From playlist Topology

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Topology: Interior, Exterior and Boundary

This video is about the interior, exterior, and boundary of sets.

From playlist Basics: Topology

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Topology (What is a Topology?)

What is a Topology? Here is an introduction to one of the main areas in mathematics - Topology. #topology Some of the links below are affiliate links. As an Amazon Associate I earn from qualifying purchases. If you purchase through these links, it won't cost you any additional cash, b

From playlist Topology

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Topology 1.3 : Basis for a Topology

In this video, I define what a basis for a topology is. Email : fematikaqna@gmail.com Code : https://github.com/Fematika/Animations Notes : None yet

From playlist Topology

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Finding Closed Sets, the Closure of a Set, and Dense Subsets Topology

Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys Finding Closed Sets, the Closure of a Set, and Dense Subsets Topology

From playlist Topology

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Topology 1.1 : Open Sets of Reals

In this video, I give a definition of the open sets on the real numbers. Email : fematikaqna@gmail.com Code : https://github.com/Fematika/Animations Notes : None yet

From playlist Topology

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Definition of a Topological Space

Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys Definition of a Topological Space

From playlist Topology

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The Homework Problem That Started as a Phd Thesis: 14 set theorem

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From playlist The New CHALKboard

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What is a Manifold? Lesson 2: Elementary Definitions

This lesson covers the basic definitions used in topology to describe subsets of topological spaces.

From playlist What is a Manifold?

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Antonio Rieser (03/29/23) Algebraic Topology for Graphs & Mesoscopic Spaces: Homotopy & Sheaf Theory

Title: Algebraic Topology for Graphs and Mesoscopic Spaces: Homotopy and Sheaf Theory Abstract: In this talk, we introduce the notion of a mesoscopic space: a metric space decorated with a privileged scale, and we survey recent developments in the algebraic topology of such spaces. Our ap

From playlist AATRN 2023

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Infinite Intersection of Open Sets that is Closed Proof

Infinite Intersection of Open Sets that is Closed Proof If you enjoyed this video please consider liking, sharing, and subscribing. You can also help support my channel by becoming a member https://www.youtube.com/channel/UCr7lmzIk63PZnBw3bezl-Mg/join Thank you:)

From playlist Topology

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What is the Mordell-Lang problem?

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From playlist Mordell-Lang

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MAST30026 Lecture 13: Metrics on function spaces (Part 1)

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From playlist MAST30026 Metric and Hilbert spaces

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Advanced General Relativity: A Centennial Tribute to Amal Kumar Raychaudhuri (L3) by Sunil Mukhi

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From playlist Lecture Series- Advanced General Relativity: A Centennial Tribute to Amal Kumar Raychaudhuri -2023

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Galois theory: Algebraic closure

This lecture is part of an online graduate course on Galois theory. We define the algebraic closure of a field as a sort of splitting field of all polynomials, and check that it is algebraically closed. We hen give a topological proof that the field C of complex numbers is algebraically

From playlist Galois theory

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Markus Haase : Operators in ergodic theory - Lecture 3 : Compact semigroups and splitting theorems

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From playlist Dynamical Systems and Ordinary Differential Equations

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Abstraction - Seminar 2 - Resolution I, blowing up

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From playlist Abstraction

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BAG1.1. Toric Varieties 1 - Affine Varieties over C

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From playlist Basic Algebraic Geometry

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Closed Intervals, Open Intervals, Half Open, Half Closed

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From playlist Calculus

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Topological space | Metric space | If and only if | Closure (topology) | Algebraic closure | Finite set | Topology | Clopen set | Isolated point | Net (mathematics) | Intersection (set theory) | Continuous function | Lower limit topology | T1 space | First-countable space | Kuratowski closure axioms | Duality (mathematics) | Map (mathematics) | Complement (set theory) | Inclusion map | Rational number | Sequence | Empty set | Derived set (mathematics) | Boundary (topology) | Filter (set theory) | Infimum and supremum | Dense set | Open set | Ball (mathematics) | Union (set theory) | Filters in topology | Real number | Sphere | Euclidean space | Category (mathematics) | Subset | Interior (topology) | Limit of a sequence | Subcategory | Trivial topology | Adherent point | Complex number | Subspace topology | Comma category | Discrete space | Complete metric space | Power set | Closed set