On the decomposition of lattices

A lattice in euclidean space which is an orthogonal sum of no ntrivial sublattices is called decomposable. We present an algorithm to construct a lattice’s decomposition into indecomposable sublattices. Similar method s are used to prove a covering theorem for generating systems of lattices and to speed up va riations of the LLL algorithm for the computation of lattice bases from large generating s ystems.