Definition:Loop (Topology)/Null-Homotopic Loop

Definition
Let $T = \struct {S, \tau}$ be a topological space.

Let $\gamma$ be a loop in $T$. Suppose $\gamma$ is path-homotopic to a constant loop.

Then $\gamma$ is said to be null-homotopic.

Also see

 * Definition:Null-Homotopic