Easter report.

I ended the last lecture before the Easter vacation by formulating Prposition 2.30, but without proof.  This section (on degrees of selfmaps of spheres) is fundamental for the definition of Cellular Homology and later applications.  The next lecture will be Tuesday, April 2.

Here are some good and instructive exercises from the material we have just covered:

Page 132-33: 17, 26, 27, 28, 29