Braided equivariant crossed modules and cohomology of Γ-modules.

If Γ is a group, then braided Γ-crossed modules are classified by braided strict Γ-graded categorial groups. The Schreier theory obtained for Γ-module extensions of the type of an abelian Γ-crossed module is a generalization of the theory of Γ-module extensions. [ABSTRACT FROM AUTHOR]