Comments on WG11 N197 (EXPRESS Ed2 Annex G)

[Phil Spiby]

Peter,

I would like to respond to your paper on Annex G.

I think you position that this annex is "Fundamentally flawed" is an
overstatement of the current situation.

Taking your points individually:

The definitions for "long form", "short form" etc are expected to be
covered in a revised version of Part 1, this was recommended at the
Stockholm meeting (Not sure if this message was passed on since I was
only there for one and a half days)

I like your idea of a two stage process, this would enable support for
E2 longform implementations (if the rest of WG11 doesn't sort itself out
and deal with shortform correctly [it was argued that by specifically
NOT supporting E2 longform we could impact the implementation methods
and force them to adopt the short form!])

E2 to E1 (longform) does not, I believe, impact the semantics, it does
however cause the creation of a number of global rules etc. which some
will find objectionable.

Short to Long does impact the semantics, and has therefore always been
argued against by the EXPRESS committee, however, since the current
implementation forms only deal with single schema models we have to
accept that this is the case. A formal mapping may be created which
ensures that the semantics are not perverted, however this would
probably cause an explosion of global rules required to deal with
independent insatiability etc.

The multi-rooted schema versus single rooted schema was not identified
as being required! All the SC4 based (and as far as I know non-SC4!)
base their implementations of defining either a single (long form) or
single (short form) schema as the target for implementation. I have seen
no implementations based on implementing an arbitrary collection of
connected schemas. Is this really a need that we have overlooked? It
certainly isn't needed within SC4.

The "empty box" mentioned in the annex is the [] symbol as used in annex
C.

Phil

> -----Original Message-----
> From: owner-wg11 at steptools.com 
> [mailto:owner-wg11 at steptools.com] On Behalf Of Wilson, Peter R
> Sent: 19 September 2002 23:44
> To: 'sc4sec at tc184-sc4.org'; 'wg11'
> Cc: Wilson, Peter R
> Subject: Comments on WG11 N197 (EXPRESS Ed2 Annex G)
> 
> 
> 
>     Attached are my comments on the EXPRESS Edition 2 Annex G 
> describing a short to long form algorithm.
> 
>     My summary statement is that Annex G is fundamentally 
> flawed and must be rewritten.
> 
> Peter W.
> 
> Dr Peter R. Wilson
> Boeing Commercial Airplanes
> PO Box 3707, MS 2R-97, Seattle, WA 98124-2207
> Tel: (206) 544-0589, Fax: (206) 544-5889
> Email: peter.r.wilson at boeing.com
> --------------------------------
> Any opinions expressed above are personal;
> they shall not be construed as representative of any organisation.
> --------------------------------
>  
> 
>