Monday:
 Write up: (1) Draw pictures of all nonisomorphic graphs on 4 vertices;
(2) Find a theory of graphs which has models of all even sizes but none of any odd size.

Wednesday:
 Write up: (1) Find out what a group is, and compose a set of axioms for groups
in a language with constant "1" (for the identity), a binary operation (multiplication)
and a unary operation (inverse). (2) Do the same with just "1" and a binary operation
intended to stand for "x times (y inverse)".

Friday:
 Write up: A lattice is a poset in which every two
elements have a least upper bound and a greatest lower bound. (1) Give
axioms for the theory of lattices, in the language of posets (just a binary
relation for "less than"). (2) Can you define the "less than" relation in
a lattice which comes only with binary operations for lub and glb?
