## Computing fixed closures in free groups

Ventura, Enric
##### Description
Let $F$ be a finitely generated free group. We present an algorithm such that, given a subgroup $H\leqslant F$, decides whether $H$ is the fixed subgroup of some family of automorphisms, or family of endomorphisms of $F$ and, in the affirmative case, finds such a family. The algorithm combines both combinatorial and geometric methods.
Comment: 10 pages
##### Keywords
Mathematics - Group Theory, 20E05, 20E36