[lojban] Sets and classes

[Pierre Abbat <phma@webjockey.net>]

In mathematical usage, "class" is {klesi} (or maybe {zilkle} since x2 is 
always sets) and "set" appears to be {selcmi}. But what of the empty set? {} 
selcmi noda, and {selcmi noda} is equivalent to {na selcmi}. So what is the 
word for "set"?

phma