I haven't reviewed this but here a URL about EXPRESS...
I have a partial copy of the ISO 10303-11 EXPRESS std document tho its
truncated just before the EXPRESS-G section. I'll download it to
the /eda.org:/pub/dcwg area as soon as I finish trying to find
an UN-truncated copy.
Now - some words about EXPRESS and representing information.
- If you feel you have to be an EXPRESS expert to read an EXPRESS model
(say about constraints), and you are RIGHT, then the model probably is
no dang good (thats a Texas phrase.. :-).
- The GOAL of a GOOD EXPRESS model is that a person knowledgeable in the
field the model is about should be able to read and understand the model
(maybe you do have to know or accept just a little about the syntax, but
not much.)
- The EXPRESS-G graphic view of the EXPRESS should be especially easy
to understand.
- ...but if the names don't mean anything and how things are related
to one another doesn't seem understandable right off the bat, then
the model's not (yet) stated from OUR point of view as designers
and EDA developers.
- There is maybe one other applicable point. There is seldom a
SINGLE perfect or correct way to write the model. Its almost always
somewhat arbitrary about the frame of reference. The only metric to
apply, again, is: Can YOU understand what its saying about the MEANING
of the informaton?
... the rest is just syntax.
--Steve Grout
SEMATECH
------- start of forwarded message (RFC 934 encapsulation) -------
From: "James A. St. Pierre" <jimstp@eeel.nist.gov>
Sender: jimstp@sparky.eeel.nist.gov
To: Steve Grout <Steve.Grout@SEMATECH.Org>,
Michael McCaleb <mccaleb@eeel.nist.gov>
Subject: This slide show will give you a short overview of the ISO 10303
Express data modeling language
Date: Tue, 12 May 1998 13:34:41 -0400
Steve,
We're still looking for any SC4 or NIST provided tutorial on
Express... so far no luck, but I'll keep digging, in the meantime we
did find this commercially available on-line tutorial WHICH HAS NO
RELATIONSHIP TO NIST WHAT so ever!! But I thought you might be
interested so I'm passing it along for your review and
consideration... we've not reviewed it so we can't vouch at all for
it's accuracy etc... it is strictly use at your own risk ;-)
http://www.epmtech.jotne.com/learn/expresscourse/sld001.htm
Jim
------- end -------
--Boundary_(ID_M9O1jIBpn/jWMi+jXhueoQ)--