n CPS --
that was the code for &quot;Com-Puter Science&quot; at Michigan State
in those days -- to work on a problem from my chemistry class,
namely, computing the covalent bonding graphs of the molecules
that could be formed from given atomic ingredients -- taking in
things like C, Cl, H, K, N, Na, O, P, S, and so on, and printing
out things like H:O:H and so on.  It gave me migraines.  And the
good of the effort was mostly just the exercise, as it takes all
the quantum mechanics of molecular orbital theor