We study the Birman exact sequence for compact 3--manifolds, obtaining a
complete picture of the relationship between the mapping class group of the
manifold and the mapping class group of the submanifold obtained by deleting an
interior point. This covers both orientable manifolds and non-orientable ones.Comment: 30 pages, no figures. v2: Major re-write following referee
suggestions. To appear in Bull. Lond. Math. Soc.; v1: This paper gives an
alternative, more algebraic, proof of the main result of arXiv:1310.7884
(with less exposition
