Admin

<csma> http://lists.w3.org/Archives/Public/public-rif-wg/2010Mar/att-0038/09-rif-minutes.html

<csma> PROPOSED: accept the minutes from MArch 9

<csma> RESOLVED: accept the minutes from March 9

Action Item Review

<ChrisW> close action-993

<trackbot> ACTION-993 Contact jderoo about DTB support or get from implementation report closed

<ChrisW> close action-992

<trackbot> ACTION-992 Contact changhai about DTB support closed

<ChrisW> close action-991

<trackbot> ACTION-991 Contact chime about DTB support closed

<ChrisW> close action-988

<trackbot> ACTION-988 Add note to BLD, Core about plain literals closed

close action-942

<trackbot> ACTION-942 Draft reponse to TK3 (Thomas Krekeler) closed

close action-938

<trackbot> ACTION-938 Draft reply to public comment AR4 closed

close action-824

<trackbot> ACTION-824 Review PRD operational and model=theoretic conditions are = closed

close action-990

<trackbot> ACTION-990 Contact Mike Dean and ask which DTB type are supported closed

close action-989

<trackbot> ACTION-989 Contact mdean for list of datatypes closed

Public comments

sandro: need to respond to public comment from Paul Gearon on 2009-11-5

<ChrisW> ACTION: sandro reply to paul gearon [recorded in http://www.w3.org/2010/03/16-rif-minutes.html#action01]

<trackbot> Created ACTION-994 - Reply to paul gearon [on Sandro Hawke - due 2010-03-23].

<ChrisW> ACTION: chris to update public comments list [recorded in http://www.w3.org/2010/03/16-rif-minutes.html#action02]

<trackbot> Created ACTION-995 - Update public comments list [on Christopher Welty - due 2010-03-23].

SPARQL use of RIF namespace

<ChrisW> Sandro summarizes issue from sparql wg

<ChrisW> ... want to use sparql to use results of rif inference

sandro: issue is we want to use sparql to query
... sparql works on graphs
... to apply to rif, query a graph that imports rif

so sparql would have rif import

<AxelPolleres> SPARQL can define what rules to refer to, only if we have a handle from the graph to the rules.

<AxelPolleres> yup.

sandro: invites people to help, expects sparql group will have doc to review in a couple months
... rdf syntax for rif has no semantics, must use axel's import to give meaning to the rules

<AxelPolleres> we thought that defining such mechanism using a rif: owned URI would be better than a sparql: uri, since importing rif rules from RDF... and there meaingin to a triples/graphs entailed by the resp. rif-rdf-combination, may be of wider interest than SPARQL only.

csma: is rif entailment in rdf graph?

sandro: yes
... may have several import profiles to address some corner cases

csma: why use rif namespace?

sandro: seems natural if in rdf and want to include rif, to use rif namespace

<AxelPolleres> rif-owned URI would be better than a sparql: uri, since importing rif rules from RDF... and thereby meaning to a triples/graphs entailed by the resp. rif-rdf-combination, may be of wider interest than SPARQL only.

<AxelPolleres> +1 to sandro

<AxelPolleres> like owl:imports

csma: but the import stmt is in the sparql spec, so I expect to see sparql URI

<AxelPolleres> we assumed that such mechanism is potentially of wider use than sparql only

<AxelPolleres> ... thus more natural in rif:

sandro: could be in any namespace (e.g. make up a new one) but easier for users to have fewer
... we should review the working draft and see if it is clear

chris: seconds Sandro

<sandro> chris: let SPARQL proceed using RIF namespace; we'll review future drafts to make sure they use it reasonably well.

<sandro> (general agreement)

CR exit

<csma> http://www.w3.org/2005/rules/wiki/Exit_Criteria

<sandro> http://www.w3.org/2005/rules/wiki/CR_Exit

csma: missing 1 core impl

chris: we have a schema validator

sandro: but there may be syntax that is not schema validatable

<sandro> schema can't tell if you're in Core or in a dialect that allows free variables.

csma: would have to check no equality in head, only ground lists, etc

<sandro> (but I would argue that such a dialect is evil --- all extensions must include some syntactic marker of that extension)

csma: is a schema-validator enough?

sandro: I think so

<sandro> sandro: Although there may be pathological dialects which cannot be distinguished from core, that's the failure of the dialect.

sandro: if you cannot distinguish a dialect from Core using schema validation, you have a poorly designed dialect

csma: we consider a Core schema validator sufficient to meet the exit criteria

IRIS implements all of DTB

<csma> # ( ?arg1; pred:is-literal-boolean( ?arg1 ) )

<csma> # ( ?arg1; pred:is-literal-PlainLiteral ( ?arg1 ) )

<csma> # ( ?arg1; pred:is-literal-XMLLiteral ( ?arg1 ) )

<csma> # ( ?arg1; pred:is-literal-not-boolean( ?arg1 ) )

<csma> # ( ?arg1; pred:is-literal-not-PlainLiteral ( ?arg1 ) )

csma: we are missing a small number of DTB builtins to have 2 impls of each

<csma> # ( ?arg1; pred:is-literal-not-XMLLiteral ( ?arg1 ) )

sandro: there could be other bits of other specs (PRD, etc.) that are not complete

csma: some of the larger PRD test cases have no XML

we are missing some test coverage

csma: and no impl (ILog, Oracle) passes all the PRD tests

sandro: need to set the "bar". Highest is we test all impls. We aren't going to do that. More practical is to lower the bar.

chris: e.g. OWL had some test cases that were never implemented.

<sandro> see http://www.w3.org/2003/08/owl-systems/test-results-out#bycount and you see for OWL 1 there were zero test cases with nothing passing them and 8 test cases with only one system passing them.

csma: is it ok to exit without good impls but with promising implementations in the works?
... e.g. current impls may require some "fixup" by hand

sandro: I think that is probably enough

for BLD we have IRIS, Vampire prime, and Silk implementations

scribe: also Eye but some confusion about its lack of XML parser

chris: unioned DTB support from all reported implementations, RIFle, OBR, Eye to determine short list of missing builtins

<ChrisW> http://www.w3.org/2005/rules/wiki/Implementations

<Harold> http://www.w3.org/2005/rules/wiki/RIF_FLD_Dialects

csma: how can Eye be a consumer if it does not consume RIF XML?

chris: also fuxi has no parser (?)
... must be using some other "presentation syntax"

csma: RDF support is the biggest issue

sandro: need rdf parser that can generate frames
... plus need to pass import test cases

chris: RIFle has some RDF import support

csma: but RIFle is only a validator, cannot pass entailment tests for import

sandro: will try to implement RDF import soon

<Harold> Implementations update DONE.

<ChrisW> thanks