A mob is a word used for a topological semigroup which is a Hausdorff space. A clan is a compact connected mob with a two-sided identity element.


Who used these words with these meanings first and when? Why were these words chosen? I'm guessing it's a play on "group", but is it really?



Who coined "mob" and "clan" and why these words?
The mob/clan terminology goes back to [Alexander Wallace](http://www-history.mcs.st-andrews.ac.uk/history/Biographies/Wallace_Alexander.html):


* [A note on
mobs](http://www.ams.org/mathscinet-getitem?mr=0053120) (1952).
* [The
structure of topological semigroups](http://www.ams.org/journals/bull/1955-61-02/S0002-9904-1955-09895-1/S0002-9904-1955-09895-1.pdf) (1953).


