Deleted inc-tick
Changed abbrev of communic ns to cm
Switched back to three-person pop
Added doall back into once.

Without the doall, if map is passed as mapfn, then you have a
lazy seq produced by map, inside a lazy seq produced by iterate
in many-times.  This produces odd and confusing effects because
you can realize the iterate seq very quickly, without realizing
any persons, i.e. without realizing the intervening maps.
More comments.