In reply to Brian Keefer <mgomes21 at cox.net>:
	This version (too many versions for such a simple thing!) follows the
	fixes reccommended by Mr. O'Keefe. I'm even going along with the #=
	sentinel comparison in removeOccurancesOf:. 
	
There is no "a" in "occurrences".

	On a completely different matter, is Object>>hash safe?  It
	seems to use the OOP address (as in a C pointer), which could change
	with each incremental GC.

Isn't that what 'rehash' is for?