=== more rigorous track (1/24/00)

 * numbers, their definitions, sizes of each
    - integers
    - rationals
    - reals
    - complex

 * sets {a,b,c,...}
    - union
    - intersection
    - mappings (into, onto, 1-1)

 * formal logic and various notations
    - "there exists x such that ..."
    - "for all x ... "
    - such that : " { x | x>3 }
    - if a then b
    - truth tables
    - proof by induction
    - proof by example
    - disproof by counter-example
    - proof by assuming oppisite, showing contradiction (called?)

assign for next Monday:
 - armstrong, 2.5 : Prove that an isometry is a bijection and 
    that the set of all isometric plane transformations is a group.)
 - armstrong, 2.7 : let x,y be members of group G.  Prove that 
    there exists w,z such that (1) wx=y, zw=y and (2) w,z are unique.
 - armstrong, 3.3 : Show that for an integer n, {c|c^n=1} where c is
   a complex number forms a group.  ("same" as what other group?)