Problem: given a finite-dimensional
nilpotent associative k-algebra N, find all unital associative k-algebras A such that
rad A = N. An approach: which subalgebras of DerkN are images of Lie
homomorphisms A∕N →DerkN? Here the author constructs N over very general
fields k such that the “Levi factor” of DerkN is a direct sum of orthogonal Lie
algebras o(V,b) of arbitrarily prescribed symmetric and alternate bilinear spaces. In
particular, if k is algebraically closed of characteristic zero, then every direct
sum of classical simple Lie algebras An,Bn,Cn,Dn is Levi factor of some
DerkN.