Cohomology: Cross ProductExplores cohomology and the cross product, demonstrating its application in group actions like conjugation.
Zig Zag LemmaCovers the Zig Zag Lemma and the long exact sequence of relative homology.
Derived FunctorsExplores derived functors, Ext-modules, Yoneda extensions, and derived categories in the context of extending modules.
Modules of CovariantsExplores the decomposition of the circle of the coordinate ring of a G variety into a direct sum of simple submodules.
