RE: intertwined specs

[Michael Rys <mrys@microsoft.com>]

> -----Original Message-----
> From: Bullard, Claude L (Len) [mailto:clbullar@ingr.com]
> Sent: Friday, February 16, 2001 1:53 PM
> To: Michael Rys; Simon St.Laurent; xml-dev@lists.xml.org
> Subject: RE: intertwined specs

> MSL:  well, ok as long as these are formal 
> proofs among interested parties as to the 
> correctness of parts, no problem.  If this 
> enters the production systems, it is not 
> something most will welcome outside the 
> deepgeeks with the faster propellors. So, 
> it will be an academic exercise similar to 
> the early DSSSL with Scheme/LISP.  Good 
> to have for formal work; not something 
> the production folks will want to work with 
> unless it is made *very* friendly by tools. 
> Even then...

MSL should not be exposed in its pure form. The problem with the schema spec
is that it only defines validation behaviour. This is not sufficient for
operational semantics and type systems as required by a query language. MSL
should address this and in addition give a formal foundation for the
validation. So the only way you should get in contact with MSL is by using
formally correct validators and query systems that provide you with support
for types.

> Keep in mind what someone made very clear 
> very passionately in Vancouver when this 
> SGML On The Web thing was a'bornin' and 
> people had to agree to walk away from the 
> advanced state of extant solid work:
> 
> "It has to be simple."  Jean Paoli- Microsoft

No disagreement on that. Let me add that simple means conceptually simple
(ala KISS and clean) and not simple-minded or simplistic. A formal system
may be simple but still needs a deeper understanding of the theory to fully
understand it.

Best regards
Michael

> Len 
> http://www.mp3.com/LenBullard
> 
> Ekam sat.h, Vipraah bahudhaa vadanti.
> Daamyata. Datta. Dayadhvam.h
> 
> 
> -----Original Message-----
> From: Michael Rys [mailto:mrys@microsoft.com]
> 
> I just want to point out that you do not necessarily need to learn the
> algebra to do the selection. But as with relational database 
> systems and
> SQL, it certainly does help if the queries become more complex...
>