For Monday 4/6, please read HtDC Chapters 30-31, and the material in the DrScheme Help Desk on the universe.ss Teachpack.
From the Help Desk, go to Teachpacks (this usually appears as the fifth item under "Languages") >> HtDP/ 2e Teachpacks >> 3.1 Worlds and the Universe
On my installation this resolves to:
Your installation may be different, of course.
Also, we will have a final lecture on Monday 4/13.