- From: Stan Devitt <stan.devitt@gwi-ag.com>
- Date: Thu, 11 May 2006 15:46:42 +0200
- To: 'Sandro Hawke' <sandro@w3.org>, Francois Bry <bry@ifi.lmu.de>
- Cc: Chris Welty <cawelty@frontiernet.net>, public-rif-wg@w3.org
(see below for comments) -----Original Message----- From: public-rif-wg-request@w3.org [mailto:public-rif-wg-request@w3.org] On Behalf Of Sandro Hawke Sent: Thursday, May 11, 2006 2:44 PM To: Francois Bry Cc: Chris Welty; public-rif-wg@w3.org Subject: Re: soundness and semantics ... (deleted) ... > 2. Such an interchange is only possible if the original semantics of > the rules and rule sets to be interchanged is specified. Therefore, > the possibility to specify a semantics for a rule or rule set should > be a requirement. That only comes up if there were rulesets with the same syntax by different semantics, right? But that's only one approach: we could use different syntax (eg different namespaces or different element names) whereever we need different semantics. I wrote about this in the notes from F2F1: http://www.w3.org/2005/rules/wg/wiki/Semantics_Extensibility_Point [stan] This, by the way, is almost the approach taken in MathML. Re-use of the basic functional syntactic structure was essential from the beginning so the "definitionURL" (really a URI) attribute was explicitly required whenever the "Default semantics" were violated. The definitionURL attribute qualified the mathematical meaning, much in the spirit of xmlns, but in a way that allowed re-use of the underlying syntax and the syntactic validation mechanisms. I suspect all our RIF dialects can also use a common syntax (to be identified) and that a similar mechanism could flag divergence from a default meaning. To my mind the reasons we did not go to simple reliance on a pure namespace based distinction included a strong desire for a static syntax. - This helped to ease validation, distribution of documents, etc., and the mathematical extensions come in how you use that notation. - It made it possible to identify the syntactic role of an object and with that some understanding of it, e.g. that it was a function) without knowing anything about it beyond that. - Once you switched namespaces, all bets as to meaning were off and the machinery to extend the structure in a way that recaptured or preserved some of that syntactic structure, while available, was much more sophisticated than just choosing a URI. There was also a relative absence of namespace mature applications at that time and we also wanted wide distribution :) (The missing piece is the algebra of dialects.) [stan]
Received on Thursday, 11 May 2006 13:46:53 UTC