The fundamental group of a locally finite graph with ends

Abstract

We characterize the fundamental group of a locally finite graph G with ends combinatorially, as a group of infinite words. Our characterization gives rise to a canonical embedding of this group in the inverse limit of the (free) fundamental groups of the finite subgraphs of G.

38 pages. This is an extended version of the paper "The fundamental group of a locally finite graph with ends" by the same authors. It differs from that paper only in that it offers proofs for Lemmas 2, 4, 6, 7, 8, 9 and 20, and a longer example in Section 5