- From: Vincent, Paul D <PaulVincent@fairisaac.com>
- Date: Fri, 10 Feb 2006 06:26:05 -0800
- To: <public-rif-wg@w3.org>
Good point. - rules can be defined and executed declaratively OR procedurally - rule conditions and actions can be order dependent or independent (cf declarative vs procedural) Although procedurally defined / executed rules are not very interesting to the academic community (I suspect), they are very common in areas such as BPM and workflow. However, as I did not note any use cases for (interchange of rules for) workflow it could be that procedural rules are not relevant to RIF. Order dependency for rule conditions is probably not much of an issue other than to rule engine writers. Order dependency for rule actions / consequents will probably depend if the rule is "logical rule" or an "executable process rule" - in the latter case it could be important (eg my actions could be order-dependent: I set the customer account to invalid and THEN send the email to the customer). Paul Vincent Fair Isaac Blaze Advisor --- Business Rule Management OMG Standards for Business Rules, PRR & BPMI mobile: +44 (0)781 493 7229 ... office: +44 (0)20 7871 7229 -----Original Message----- From: public-rif-wg-request@w3.org [mailto:public-rif-wg-request@w3.org] On Behalf Of Axel Polleres Sent: Friday, February 10, 2006 2:11 PM To: Christopher Welty Cc: public-rif-wg@w3.org Subject: [RAF] small comment on discriminator "declarative vs. procedural" Dear Chris, I had some discussion with Harold about the "declarative vs. procedural" discriminator mentionedin the RAF wiki page (see mails below). Basically, I think that the discriminator "declarative vs. procedural" does not properly reflect the text: " what was meant here is the availability (or not) in a rule of procedures (expressed in some programming language) that perform computations (such as doing arithmetic) that are difficult or impossible to express in logic" at http://www.w3.org/2005/rules/wg/wiki/Rulesystem_Arrangement_Framework Is IMHO misleading: In LP usually one understands the different between procedural and declarative in the sense that the order of rules does not play a role for the semantics, i.e. that a set of rules is indeed handles as a set with a declartive semantics. This is at least the main issue which gives PROLOG its procedural style vs declarative logic programming. It is not necessary about arithmetic or procedural attachments alone. So, I'd suggest to change thw current heading for this discriminator to something like "builtins vs. no builtins" and redefine the discriminator "declarative vs. procedural" as a new one. best, axel -------- Original Message -------- Subject: RE: [RAF] small comment Date: Fri, 10 Feb 2006 08:52:20 -0500 From: Boley, Harold <Harold.Boley@nrc-cnrc.gc.ca> To: <axel@polleres.net> Hi Axel, > This is mostly what I meant. I will look at this in detail asap. I now found the time to see that you commented on the RAF part recently changed by ChrisWelty, going back to F2F1 breakout session notes by PascalHitzler. I did not add explanations to their parts. However, I alluded to a distinction in: "For example, since the [WWW] Phase 1 rule semantics will be essentially Horn Logic, the "procedural vs. declarative" Discriminator (along with many "procedural" Subdiscriminators) of the "Suggested discriminators ..." could be added for Phase 2." I agree with you that this "procedural vs. declarative" distinction is not quite the same as in LP. The problem may have to do with the distinction of "procedural attachments vs. no procedural attachments" (which I would therefore rename into "builtins vs. no builtins"): This latter one is the one, I guess, ChrisWelty's comment refers to. After your comment, my suggestion would now be to clearly separate these distinctions, at least as subdistinctions. You can modify/forward this email to ChrisWelty. Best, Harold -----Original Message----- From: Axel Polleres [mailto:axel.polleres@uibk.ac.at] Sent: February 9, 2006 10:14 AM To: Boley, Harold Subject: [RAF] small comment Boley, Harold wrote: >> [NEW] ACTION: Harold will explain what Lloyd Topor extensions etc >> mean > > [recorded in http://www.w3.org/2006/01/31-rif-minutes.html#action18] > > I updated the > http://www.w3.org/2005/rules/wg/wiki/Rulesystem_Arrangement_Framework > section "Phase 1 Expressive Discriminators", part "Syn: Syntactic > Discriminators", adding brief explanation sub-bullets plus links > (except for the self-explaining item 1.). Hi Harold! I have a small comment on the RAF page: > procedural vs. declarative: Rules are generally declarative, I assume > what was meant here is the availability (or not) in a rule of > procedures (expressed in some programming language) that perform > computations (such as doing arithmetic) that are difficult or > impossible to express in logic In LP usually one understands the different between procedural and declarative in ther sense that the order of rules does not play a role for the semantics, i.e. that a set of rules is indded handles as a set with a declartive semantics. This is at least the main issue which gives PROLOG its procedural style vs declarative logic programming paradigms, right? It is not necessary about arithmetic or procedural attachments alone. best, axel -- Dr. Axel Polleres email: axel@polleres.net url: http://www.polleres.net/ -- Dr. Axel Polleres email: axel@polleres.net url: http://www.polleres.net/
Received on Friday, 10 February 2006 14:26:25 UTC