Re: Sets etc.

[John Cowan <jcowan@reutershealth.com>]

pycyn@aol.com wrote:

> A class is [...]. A set is [...] A mass (in the Lojban
> sense) is [...].

What oft was thought, but ne'er so well expressed.

> Finally, a class may
> be viewed collectively, and then the properties attributed to it have little
> to do with the properties of the individual but rather with matters like how
> many there are of them or (more related to their proerties) what toher
> classes they belong to -- cardinality, inclusion, and the like -- set
> theoretic properties, in short, which only rarely have value in ordinary
> discourse.

I brought up "ralju" psecisely to mention a "non-mathematical" use of classes/sets.
There is no reason why there should not be a branch of set theory dealing
with the "most important" members of sets, but it happens there is not.

Which leads me to the following challenge, due to Quine. A student at Yale
may belong to zero or more clubs. Some clubs are final clubs. A final
club is defined as "a club such that membership in it precludes membership in
any other final club".

Express the definition of "final club" in good Lojban without circularity.

-- 

Schlingt dreifach einen Kreis vom dies! || John Cowan <jcowan@reutershealth.com>
Schliesst euer Aug vor heiliger Schau, || http://www.reutershealth.com
Denn er genoss vom Honig-Tau, || http://www.ccil.org/~cowan
Und trank die Milch vom Paradies. -- Coleridge (tr. Politzer)