### Week 0: September 7-8, 2017.

Required Reading: Appendices A and B (notions of set theory, functions), including things that were not covered in class. You are expected to know some basic set-theory notions
from high school, although the intersections and unions of infinitely many sets may be new. Try to absorb the material on relations (even though not covered in class).
In class, we also discussed cartesian products of two sets.