Certain generating subspaces for vertex operator algebras

Minimal generating subspaces of "weak PBW type" for vertex operator algebras are studied and a procedure is developed for finding such subspaces. As applications, some results on generalized modules are obtained for vertex operator algebras that satisfy a certain condition, and a minimal generating space of weak PEW type is produced for V-L With L any positive-definite even lattice. (C) 1999 Academic Press.