Homework problem sets

  1.  Due in class on Tuesday, February 6, 2016: do Exercise 16.1.16, and use it to write up a careful proof of Lemma 16.2.18.
  2. The second homework set will not be collected.
  3. Due in class on February 23, please do all six parts of Exercise 19.3.22 from your book (page 343).  This will be graded as the first exam.