The purpose of this article is to prove that the category of cocommutative
Hopf K-algebras, over a field K of characteristic zero, is a semi-abelian
category. Moreover, we show that this category is action representable, and
that it contains a torsion theory whose torsion-free and torsion parts are
given by the category of groups and by the category of Lie K-algebras,
respectively
