In this paper, we construct the projective resolution of arbitrary symmetric 2-group, define thederived 2-functors in (2-SGp) and give some related properties of the derived 2-functors.
In this paper,we give the notion of derivations of Lie 2-algebras using explicit formulas,and construct the associated derivation Lie 3-algebra.We prove that isomorphism classes of non-abelian extensions of Lie 2-algebras are classified by equivalence classes of morphisms from a Lie 2-algebra to a derivation Lie 3-algebra.
In this paper, for the highest weight module V4 of sl（2,C） with the highest weight 4, we describe subalgebras Sβ（V4）＋ and Sγ（V4）＋ of the βγ-system coset S（V4）＋ by giving their generators. These eoset subalgebras are interesting, new examples of strongly finitely generated vertex algebra.
