Derived considerations

The Nygaard filtration and foundations for the last four talks.
Define filtered derived categories (Construction 8.4.1) and the Beilinson
t-structure (Remark 8.4.8). Use Proposition 8.4.10 as a definition for the
functor Lηp, and give a more explicit description relating it to the functor
ηp of §2.1. Discuss Proposition 7.2.4, Theorem 7.4.7 and Corollary 7.4.8.
Finally, define the Nygaard filtration as in Proposition 8.4.11. As time
permits, come back to some descriptions and properties in §8.1 and §8.2.