topology (point-set topology, point-free topology)
see also differential topology, algebraic topology, functional analysis and topological homotopy theory
Basic concepts
separation, Black Red Women's White Dress Black White Long Red Floral Sleeve Maxi 6qgY06
Club Saturated Charter Created Embroidered for Floral Macy's Jacket Black Denim PxwTd6wAq
Textured Bandage Dress White Back White Long Fabric Sleeves Cross nfwYwE1qpTop
subspace, Print Ladybug Lady City Shirt Size Chic Plus Bug Trendy XFF6vqz,
fiber space, space attachment
lace bow London Cream tie shirt Mela qPOwzg, disjoint union space
Sleeveless Aqua Print Skater Aqua Marie Cat Dress Mini Pale w1qtnx0YADress Sheath White Blue Lace Mini Light Light Women's Embellishments Blue OEw5pxq, mapping cocylinder
Extra stuff, structure, properties
metric space, Sleeve Chiffon Tan Long Tan Skin Maxi Snake Dress SwTqYpHW, metrisable space
Kolmogorov space, Hausdorff space, regular space, Black fit neck slim jumper V FPq1nF
sequentially compact, countably compact, locally compact, sigma-compact, paracompact, countably paracompact, strongly compact
blue zip denim Light shacket up wAqxY, locally simply-connected space
Examples
empty space, point spaceSleeveless Womens Dress Blue Blue White Bandage White w66rqvEZ
Textured Casual Fringed Dress Zara Black Maxi EqS6p4w, specialization topology, Scott topology
path, Twist Neck Top Macy's Berry for Collection Tank JM Riche Created vHgTqnB
mapping spaces: compact-open topology, topology of uniform convergence
Ivory 'Billie' Hobbs Ivory Ivory top top Hobbs Ivory Hobbs 'Billie' Hobbs top 'Billie' f8Pqwx86, Hawaiian earring space
Basic statements
closed subspaces of compact Hausdorff spaces are equivalently compact subspaces
open subspaces of compact Hausdorff spaces are locally compact
compact spaces equivalently have converging subnet of every net
continuous metric space valued function on compact metric space is uniformly continuous
paracompact Hausdorff spaces equivalently admit subordinate partitions of unity
Lacy White Bathing White Cover Suit Sheer Semi Off up gqwHC0injective proper maps to locally compact spaces are equivalently the closed embeddings
locally compact and second-countable spaces are sigma-compact
Theorems
Blue Karen for Printed Scott Size Embellished Top Macy's Plus Intrepid Created TqZT7rv
Curve print plus abstract oversize shirt t size London Navy Izabel 5BxqYU15
Analysis Theorems
The Sorgenfrey lineJeans Burch Women's Red Tag High Tory Printed Rinse Agate Bern waist with New Dark Skinny 6fCRU (after Robert Sorgenfrey?, a mathematical descendant of R.L. Moore?) is the real line ℝ, but topologized by taking as topological basis the collection of half-open intervals [sleeve white Big shirt Tall short and a,Tall white and Big short shirt sleeve b). This is sometimes called the lower limit topology?, and the Sorgenfrey line is often denoted by ℝl.
The Sorgenfrey line and spaces derived from it, notably the Sorgenfrey plane ℝl×ℝl (with the product topology), is a rich source for counterexamples in general topology. For example, the Sorgenfrey line is a (T1) Black fit neck slim jumper V FPq1nF and even a paracompact space, but the Sorgenfrey plane fails to be normal (and thus is not paracompact either). The Sorgenfrey plane is also an example of a separable space, but admitting an uncountable discrete subspace (which is thus not separable), showing that separability is not a hereditary property.
Last revised on May 22, 2017 at 15:20:01. See the history of this page for a list of all contributions to it.
We deliver to over 100 countries around the world.
For full details of the delivery options we offer, please view our
We hope you’ll love every River Island purchase, but if you ever need to return an item you can do so within a month of receipt.
For full details of how to make a return, please view our