Readings on OWL's (un)decidability?

Hello, 

I've seen many documents saying "OWL FULL is undecidable" ... (a)

But which of the following does (a) mean?:

(1) "There is no system which is decidable where there is a Class, say ClassA,
that is an instance of another Class."

or

(2)"There is at least one system which is undecidable where/because there is a Class, say ClassA,
that is an instance of another Class.
i.e. Not every system with a vocabulary in OWL FULL is decidable."

What do you recommend me to read for the proof of (a)?
(A (short) article on the Web is preferred to a whole book ^_^;)

Best,
Yoshio 

-- 
Yoshio Fukushige <fukushige.yoshio@jp.panasonic.com>
Network Development Center,
Matsushita Electric Industrial Co., Ltd.

Received on Monday, 2 October 2006 06:27:10 UTC