# Outline of a two-player board game, like tic-tac-toe, 
#   chess, etc:


# 1. select the data structure that models the game board
#      (maybe we will place this in a separate module...)

# 2. write the algorithm for controlling the game
#
#  while game_on :
#    print the board
#
#    ask player "X" for their move
#    do the "X" move on the board
#
#    ask player "O" for their move
#    do the "O" move on the board