TOPICS

Algebra Applied Mathematics Calculus and Analysis Discrete Mathematics Foundations of Mathematics Geometry History and Terminology Number Theory Probability and Statistics Recreational Mathematics Topology

Alphabetical Index New in MathWorld

Topology
Point-Set Topology

Topology
Algebraic Topology

Contractibility

See

About MathWorld
MathWorld Classroom
Contribute
MathWorld Book
wolfram.com

13,123 Entries
Last Updated: Sat Apr 13 2024
©1999–2024 Wolfram Research, Inc.
Terms of Use

wolfram.com
Wolfram Language
Mathematica
Wolfram Demonstrations
Wolfram for Education

Created, developed and nurtured by Eric Weisstein at Wolfram Research