http://www.w3.org/2005/rules/wg/wiki/A._RIF_Condition_Language
harold: I pasted unchanged what was in the e-mail then made one clarification change, so you can see it in the wiki history
mkifer: we had a poll on this, right?
csma: we agreed to start with a condition language, and examine this as a candidate
(in the telecon about 5 weeks ago, as I recall)
Axel: my review
... Slotted syntax, as in F-logic and WRL.
... My languages are WRL and DLV
... Has extensions for aggregates, etc
... so missing things:
... 1. slotted
... 2. only-conjuntions vs. complex formulas? does this language only allow negation in front of atoms?
Harold: that's an extension, in A2
Axel: Builtins
go for it, Paula!
<sandro> scribeNick: PaulaP
Axel: do you allow two free variables in the condition
Michael Kifer: syntactically, yes
Axel: some languages allow binding patterns and the question is whether we should allow such patterns
Michael Kifer: yes, I think this is an issue
Axel: Phase II issues are also considered
... aggregates are also an open issue
csma: do you have something useful?
... is there an essential part that you could map and this part is useful?
Axel: yes, there is a useful part
<AxelPolleres> For the records: http://lists.w3.org/Archives/Public/public-rif-wg/2006Jun/0035
Hassan: most of Axel's comments apply also for me
... missing slots as well
... types, because objects are types
... I took the object model of IRL and put it into a logical form
... this is a way to get around with slots and other features
... aggregates are missing
Michael Kifer: types for slots or for variables?
Hassan: for both
... types a la Java
ChrisW: Is Peter on the phone?
Sandro: he is on the phone
... I guess not
ChrisW: any more discussion on this?
Sandro: I'm tenpted to do such a mapping too
... I imagine we can have a web form for mappings to RIF
csma: the same question for Hassan as for Axel...
... are there easy extensions to the condition language that are needed to cover what is missing?
Hassan: yes, we need more elaboration on XML constructs that we need
csma: we can look at some concrete examples
Hassan: I think we should all do this together
Axel: how about mapping N3 to the condition language?
... or perhaps SPARQL?
<sandro> Sandro: binary or ternary mapping to RDF ?
Harold: the text on the condition language mentions some of the issues that are needed for such a mapping
Hassan: Prolog is trivialy mapped to the condition language
csma: so we are done for phase 1
ChrisW: how about reverse mappings?
no one tried this
ChrisW: is the condition language what people expect from RIF?
... does this looks like a RIF?
csma: you also need an abstract syntax
Hassan also agrees on this
<sandro> by Abstract Syntax them mean XML Schema
Hassan: I can work on this on IRL
... we should complete this and then define what we need
... I took the grammar, annotated it and got the XML serialization
csma: Hassan should show us what he means
ChrisW: the question is what happens if one uses the condition language to interchange between WRL and IRL
Michael Kifer: we need to define the taxonomies
csma: and then to go back to this
ChrisW: an issue is the default behaviour in this particular case
Hassan: Hyperdocumentation for grammar RCL.grm
... you can specify an XML serialization by providing annotations
Sandro: did you developed this only for this application?
Hassan: we can of course generalize this to other applications
... I tried the example given in the text of the condition language and it works
... more details on the grammar definitions
... the bindings are done by using object handlers
... test expression can be very complex
... you can have a referent expression, a partial expression
... my simple annotation breaks down here
ChrisW: all these activities are useful for various reasons
... this can impact RIFRAF
csma: can you interchange a useful part of your language?
Hassan: it is useful now
Michael Kifer: the binding patterns represent the only discriminator for RIFRAF
Michael Kifer: not sure how to RIFRAF built-ins
<scribe> ACTION: Michael Kifer to describe the issue on built-ins as RIFRAF discriminator
Hassan: I don't parse XML yet
... there is no way to provide the original syntax
... this is because I use the mapping
... from IRL to AST, then get XML
the problem consists in the mapping from AST to IRL
Hassan: this is a problem if one needs to do the reverse translation
... AST doesn't know what to do with the universal
ChrisW: do you have the same problem?
... what can't you translate into WRL but you have it in the condition language?
Hassan: I didn't do the IRL
Axel: I wrote an email on descriptions of rule systems
... this goes in the same direction
... what subset of RIF do I understand?
... I need an annotation of what I understand
ChrisW: descriptions of language capabilities are needed
... for this we need such mappings
Hassan: from XML to AST, we need an XML to AST parser
... as long as I see tags that I understand, it's no problem
... I see universal now
... I don't know what to do here
csma: this is a compliance issue
Hassan: there are a couple of possibilities
ChrisW: it is important for determining appropriate behaviours
Hassan: it is before that
... AST is a bunch of Java classes
... I am RIF compliant, so I should be able to have a default behaviour represented internally
csma: we are talking about the behaviour of the translator
ChrisW: the idea is to determine the behaviour
Hassan: we need representations for such kind of behaviours
csma: a possibility is to reject rule sets
ChrisW: we should be careful not requiring changes in the rule systems
<AxelPolleres> For the records, link to my mail mentioned above: http://lists.w3.org/Archives/Public/public-rif-wg/2006Jun/0102
csma: this could be a separate program
... so no need to change rule systems
Gary: we will have a large number of discriminators
... but we want a small number of dialects
... we need to structure these discriminators
csma: some features may be optional, so we need a way to handle default behaviour
Gary: default behaviour may be in most cases 'not proces these rules'
Sandro: there are also other possible behaviours
... perhaps I want fewer results
csma: this works for publishing rule sets and using them as they are, without communication
Sandro: difference between profiles and dialects
... I can see the reason for the difference now
csma: for some use cases we might need also a kind of protocol
Gary: a negotiation is not always possible
ChrisW: it is useful for a language to describe themself
... the point of the dialects is for interoperability
Sandro: dialects need to be in the intersection of the languages to be interchanged
ChrisW: that's fine
... but the languages may have a superset that is described in their profile
Hassan: RIF compliance means that all construct I understand I can represent in RIF
... but what do you do with things that you don't understand directly?
<pfps> I don't think that it is *necessary* to be in the intersection to have useful interchange. Perhaps it may be necessary to be in the intersection of the dialects to have totally faithful interchange, but I think that useful interchange can be done even if it is not totally faithful.
Hassan: I'm RIF compliant even if I don't understand everything from RIF
Sandro: there are two modes of deployment
... inside an enterprise or between different business partners
... there are different styles
Hassan: I see what you mean but I still don't understand what your definition is
csma: your definition is ok, but we should not have many dialects
... this is the point of this discussion
... I have a problem I would like to raise
<sandro> (mode 1 allows lots of extnesions; mode 2 is strict-to-standard-dialects)
csma: on Hassan's problem with getting the original syntax
... is this depends on your implementation?
Hassan: it depends on how concrete your abstract syntax is
... if the RIF XML is abstract, then is impossible
Gary: no, it is possible but is harder to read
Hassan: I agree with Gary
csma: so you could generate some sort of IRL from the AST
Hassan: yes, it is possible but I don't know if it's readable
Gary: an example is Java
Hassan: variable names will be a problem
Sandro: very good chairing if this meeting
csma: we are even before schedule
... thanks for scribing
<Darko> -Darko
ChrisW: thanks everybody
END OF MEETING
<EvanWallace> scribes did a great job today!
<PaulV> quit