loop

In graph theory, a loop is an edge which joins a vertex to itself, rather than to some other vertex. By definition, a graph cannot contain a loop; a pseudograph, however, may contain both multiple edges and multiple loops. Note that by some definitions, a multigraph may contain multiple edges and no loops, while other texts define a multigraph as a graph allowing multiple edges and multiple loops.

In algebra, a loop is a quasigroup which contains an identity element.

Title	loop
Canonical name	Loop
Date of creation	2013-03-22 12:14:08
Last modified on	2013-03-22 12:14:08
Owner	drini (3)
Last modified by	drini (3)
Numerical id	10
Author	drini (3)
Entry type	Definition
Classification	msc 05C99
Classification	msc 20N05
Related topic	Graph
Related topic	Pseudograph
Related topic	Quasigroup