@{void} {insert(Item e);} {If the reference count of \verb+store+ is greater
			   than 1, then other collection objects are also 
			   using
			   it as their implementation.  Rather than changing
			   its contents, a copy will be made ($O(n)$), 
			   and the reference
			   counts will be updated.  Finally, check to 
			   ensure that $e$ is not currently a member, then
			   call \rar{store}{insert(e)}. to insert $e$.}@

@{void} {append(Item e);} {After considering reference counts as above, 
			   check to ensure that $e$ is not a member, then
			   call \rar{store}{append(e)}. }@

@{void} {remove(Item e);} {After considering reference counts as above, 
			   remove $e$ from \verb+store+.}@

@{int} {occurrences(Item);} 
			{ Return 1 or 0.  $O(1)$.  }@ 

@{int} {permutationQ();} 
			{ Always returns TRUE. $O(1)$.}@