# Spectral Formalization project of the CMU HoTT group towards formalizing the Serre spectral sequence. ## Things to do for Lean SS project Lang's algebra (revised 3rd edition) contains a chapter on general homology theory, with a section on spectral sequences. Thus, we can use this book at least as an outline for the algebraic part of the project. ###To Do: - R-modules, vector spaces, - some basic theory: product, tensor, hom, projective, - categories of algebras, abelian categories, ###Already Done: - definition of algebraic structures such as groups, rings, fields, - some algebra: quotient, product, free.