12:06:24 RRSAgent has joined #sml 12:06:24 logging to http://www.w3.org/2007/08/29-sml-irc 12:06:32 Zakim has joined #sml 12:14:55 Valentina has joined #sml 12:18:39 Kirk has joined #sml 12:19:10 pratul has joined #sml 12:19:34 Sandy has joined #sml 12:20:46 scribe: Valentina 12:21:05 Meeting: SML f2f second day 12:21:20 chair: John and Pratul 12:21:56 Topic: Continue debate on topic 4774 - schema binding issues 12:22:20 http://lists.w3.org/Archives/Public/public-sml/2007Aug/0087.html 12:23:52 start by reviewing section 6.2.4 12:24:13 Marv has joined #sml 12:24:42 Pratul : it seems that this is similar with something that is already available in SMLIF 12:24:54 no comments for 6.2.4, moving forward 12:25:07 review section 6.3 12:25:25 Sandy: there are no defaults here, you have to specify everything 12:26:46 Kirk: not sure why the consumer of SMLIF should go through all this validation since the SMLIF schema validation has been done already 12:27:45 MSM: requires associations between the SMLIF instance documents with the schema instances , as the producer intended 12:28:07 Kird: understands the need 12:28:43 moving to section 7.1 - Analysis 12:29:04 7.1 Namespace matching 12:30:41 Pratul: typo in 7.1 first item; If is OK even if B and D should be 'It is OK even if B and D' 12:31:37 Pratul: what is the scenario for item 3 ( exchange schema but not use it for validating SMLIF instances ) 12:32:41 Sandy: the consumer just need a new version of a schema to update its schema definition. It is not linked with any SMLIF instance document 12:34:17 John: another scenario: the user is working on some files, they are not yet ready ( not valid ) but you still want to exchange this with the consumer. The producer wants to let the consumer know that they are incomplete validation 12:34:44 s/validation/documents 12:34:51 s/Kird/Kirk 12:35:42 Pratul: a third option when exchanging incomplete documents is to not a send the definition document with the incomplete instances 12:36:11 John: there is no implication in the SMLIF spec that definition files should be used for validation 12:36:22 Paul has joined #sml 12:37:23 Pratul: if we go this path we may overcomplicate the scenarios. May probably have next a consumer who wants to send some documents and ask the consumer to only use certain documents 12:38:37 MSM: looking at the spec, it says that the producer sends the instances and the definitions to validate this documents 12:38:49 MSM: this should not be the only scenario 12:39:34 John: you can do this, the spec doesn't write it specifically this way 12:40:03 Sandy: any more comments on 7.1 ? 12:40:22 Sandy moving to 7.2 - Explicit schema binding 12:42:17 MSM: what do you mean by being more difficult than 7.1 ? 12:42:47 John: computationally is the same, the actual content of the SMLIF differs; this is where the complexity resides 12:43:28 Kumar: is 4.1 satisfied by the explicit schema binding ? 12:44:53 Sandy: you can have 4.1 only when you know that an SMLIF is incomplete; explicit schema binding proposal allows you to do that 12:45:44 Sandy: moving to section 8 - Conclusion 12:47:23 MSM: question on the Overview of ‘Explicit schema binding’ approach subsection 12:49:00 MSM: I am assuming this is a cumulative sample; don't understand why I need schema level binding if I have default namespace approach 12:53:12 Valentina: it explains what happens when you have two definition document using the same namespace while having two instance documents pointing to one/respsctive the other schema. If a global schema binding is used then at least one instance level mapping is required to support this 12:53:55 Pratul: if we don't have this case where you have two schemas with the same namespace ; do you stil lneed the schema binding ? 12:54:12 Sandy: no, you go with the default namespace matching for simple cases 12:55:14 Sandy: this is just an illustrative example on how schema binding will be appllied on conflicts 12:55:54 Pratul: assuming we go with this approach, we need to make sure we align with the rule binding approach 12:56:05 Sandy: likely but this is a next step 12:56:11 johnarwe has joined #sml 12:57:27 Sandy: comments ? 12:58:46 Partul: let's assume we don't have this duplicate schema scenario. Do we still need schema binding to support the import/include scenarios ? 12:59:09 Sandy: yes, some cases still require specific binding 12:59:42 MSM: can we have a chameleon include sample ? 13:00:29 Pratul: how schema deal with this situation ? 13:01:04 MSM: schema spec does not define an algorithm for that 13:01:42 e.g. 2 schema docs for the "empty" ns; xsd1 is really for "empty", and xsd2 to be chameleon included. then in schema binding, the global binding will have "empty -> xsd1 (leaving xsd2 out). 13:04:59 MSM: every chameleon is an orphan; is called in using the schema location 13:09:57 Sandy: for redefin, the producer decides what the algorithm to use for mapping; can be namespace match which means included in the synthetic schema . Or can use the schema binding, in which case it will have to specify the corresponding schema level binding 13:10:05 Sandy: commments? 13:10:33 Kumar: overall looks good, it tries to address all issues. Need some more work on a few issues though 13:10:43 Kumar: is this a proposal to make this a requirement ? 13:10:55 Sandy: yes; this is how we should quarantee interop 13:11:32 Kumar: in this case I am not confortable with having to support conflicting schemas. Do we know how many processors support that ? 13:12:28 Sandy: this is not a processor issue; if your app uses a processor that doesn't understand conflicting schema, the app can choose to pass the information the process can process 13:13:36 Kumar: not sure how this worl 13:13:55 Sandy: for every instance create different processor instances 13:14:14 Kumar: but I may have dependencies between instances 13:14:56 Sandy: good question; probably need to ask that those documents be compatible relative to the schema 13:15:26 MSM: this come as a comment for the definition of the model validity 13:17:01 John: at least one of the target constraint requires PSVI - I think is the target element 13:19:40 MSM: reading the description of the target type; I don't see a definition of the target type when using multiple documents 13:20:06 ..when you cross schema documents 13:20:48 s/../... 13:26:49 MSM: sample; have one instance using nl:T and n2:e. Other instance uses nl:T and n3:e 13:27:10 MSM: the two instances are compatible since they are using the same nl:T 13:27:53 Pratul: correct, but this results into an identity of the type 13:27:58 MSM: correct 13:28:52 John: think about having two schema documents having the same namespce n1:T 13:29:10 s/nl:T/n1:T 13:29:19 s/nl:T/n1:T 13:30:35 John: the only way you get around this is by requiring to use the latest schema defining n1:T 13:32:00 John: if you have backward and forward compatibility than this is safe 13:32:37 Valentina: I don't see backw and fwd compatibly as a regular scenario. Most of the time you don't have fwd compatibility 13:33:27 MSM: backf and fwd compatibility can happen you have a wildcard in the old schema which is more restricted in the new schema 13:36:02 s/can happen you have/can happen when you have 13:39:49 MSM: my point is that fwd and backward compatibily is not impossible but it is not a regular scenario 13:40:35 rrsagent, generate minutes 13:40:35 I have made the request to generate http://www.w3.org/2007/08/29-sml-minutes.html Valentina 13:40:43 MSM has joined #sml 13:43:26 John: if you have conflicting schema and you are trying to use both you can't 13:46:02 Kumar: is I send SMIF documents and have conflicting data, for consumers to generate the same result we need some information on how to validate 13:46:33 s/is I/if I 13:48:03 MSM: schema spec doesn't say anything about two type definitions describing the same thing 13:49:04 Pratul: my position is: if there are two conflicting schemas then the SML model should be marked as invalid 13:49:25 MSM: depends on the goal of SML 13:50:23 MSM: in real life is quite usual to use different versions of the same schema 13:51:34 MSM: SML model is essentially a set of xml documents; so some SML models may expect to have this conflicting situations 13:53:55 MSM: trading example: multiple companies are exchanging data 13:54:42 ...one company may use different schema for the same namespace as a corporate policy 13:55:03 ... ( different from what other company may use for the same namespace ) 13:55:38 Paul: we have a similar situation 13:56:25 Paul: have different versions of a model and some divisions use one version, some other division use a different one. We want to have this option of choosing what schema version to use 13:57:02 s/Paul/Marv 13:57:10 Kumar: but this leads to ambiguity 13:57:25 s/Paul/Marv 13:58:07 Why can't Marv not use two different namespaces 13:58:54 Marv: but it should be my choice; I want to reduce the requirements that I have to impose on the usage of a certain schema. In the end makes the spec more valuable. If we decide that this is impossible to implement that's fine but I would prefer to be able to make a choice 13:59:25 Pratul: still don't see a clear scenario where conflicting schemas are being used 14:00:07 Marv: use one schema in 2001, two years later a better version of this schema is produced 14:00:30 ... in real life, the new schema will be used but the change will not happen everywhere 14:00:44 Marv: now I am usin an CMDBf 14:01:13 s/usin/using 14:01:57 Marv: I want to be able to use the same namspace for the two versions and recognize that 14:03:50 MSM: XSLT is a schema sample where community didn't want to use different samespaces for new versions 14:13:34 MSM: we need to take into consideration what happens in real life when defining the SMLIF; don't impose a constraint on what data should be in SML model just because we think this is how the real life work it should work 14:20:08 s/the real life work/in the real life 14:24:43 Zakim has left #sml 14:26:12 rrsagent, generate minutes 14:26:12 I have made the request to generate http://www.w3.org/2007/08/29-sml-minutes.html Valentina 14:29:13 Kumar: conflicting schemas means a processor being required to support different versions of the same schema 14:29:21 John: not in the same session 14:31:33 MSM: the existing of two conflicting schemas shoudl be supported by a processor - have some sort of options on how to solve it, such as telling the processor which schema to use. The validation will not be done in the same session if two conflicting schemas are to be used 14:32:16 Pratul: we don't have a consensus on this 14:32:38 Jim: can this be made implementation specific ? 14:32:56 Pratul: is it's not defined by the interop then in my view it's useless 14:33:13 s/is/if 14:34:38 Kumar has joined #sml 14:34:39 John: we can split the interop in two parts 14:35:04 ..one is what we do now, the a second conformance section which offers more 14:35:13 s/te/then 14:35:26 s/the/then 14:36:44 Paul has joined #sml 14:36:55 Jim: some implementations may support some versions of the schema binding but not all at the options 14:37:30 Sandy: if you support schema binding then you by definition support all of the proposed options since they produce the end solution 14:39:42 John: so if a producer offers some options to do schema binding some of the consumers may choose not to support ( will ignore ) some of these options 14:40:45 John: but in this case the interop will become too complex 14:45:53 ginny has joined #sml 15:03:16 sml has joined #sml 15:05:24 zakim, who's on the phone? 15:05:30 Zakim has joined #sml 15:05:36 zakim, this is sml 15:05:36 Sandy, I see XML_SMLWG(IBM f2f)8:00AM in the schedule but not yet started. Perhaps you mean "this will be sml". 15:05:43 zakim, this will be sml 15:05:43 ok, Sandy; I see XML_SMLWG(IBM f2f)8:00AM scheduled to start 185 minutes ago 15:06:02 Pratul: conclusion on 4774 - schema binding issue - I don't think we have a consensus yet 15:06:02 johnarwe has joined #sml 15:06:30 John: to make progress for the second draft we should continue this discussion by mail 15:07:02 Pratul: propose to discuss 4774 in the next week's call 15:07:39 Kirk: should a separate action be opened to review the need of having conflicting schemas? 15:08:32 Pratul: it is already captured in 4774 proposal so for now let;s keep it there 15:09:24 Pratul: let's try to have the schema binding issue solved for the second draft so that we can have the schema group review the proposal 15:11:10 Kumar: what else should be discussed since it seems we covered everything ? 15:11:46 Pratul: have no consensus yet; there are members of the group who were not part of this discussion 15:12:34 http://lists.w3.org/Archives/Public/public-sml/2007Aug/att-0086/SML_References.html 15:12:36 Topic: Reference proposal 15:12:43 http://lists.w3.org/Archives/Public/public-sml/2007Aug/0086.html 15:15:29 Sandy: Section 1 15:15:48 Kumar: is this consistent with what is already in the spec? 15:16:20 John: SML spec has two ways of recognizing sml references 15:16:45 John: this definition covers both cases and adds now ones 15:17:56 John: current schema definition says that ref can be recognized at the schema level only by using the refType 15:18:38 s/using/extending 15:19:23 Section 2 - How are reference elements handled? 15:20:06 MSM: what means mainline ? 15:20:35 Sandy: how you handle references in deref functions 15:21:41 John: the content of an sml:uri can be a reference. In order to test for the reference, you need to call the deref. 15:22:15 John: you can replace mainline with the implementation of every refence scheme the consumer recognizes 15:23:30 Sandy: moving to the list under 'The general form for handling non-null references is shown below.' 15:24:48 Kumar: should we have a 2.1 a case where none of them resolve ? 15:25:03 s/ a 2.1/in 2.1 15:25:19 Sandy: yes, we need this 15:26:31 Pratul: why 2.1 ? ( a consumer MUST attempt the validation .. ) 15:27:14 Pratul: it feels that the validator is forced to do all options 15:27:28 John: your processor recognizes only some schemes 15:28:26 Sandy: validators are special case of consumers 15:29:07 Kumar: in 2.2, the consumer si required to validate at least one ? 15:29:16 s/si/is 15:29:45 MSM: if I support a scheme, am I required to validated ? 15:29:53 John: good question 15:30:09 s/validated/validate it 15:31:19 Pratul: if we have section 2.2 we allow to have two things in the spec: one which is the validator and the other which is a consumer 15:31:53 Sandy: to answer MSM question : if you recognize a scheme but you didn't try to validate any of them, then is in violation with 2.2.3 15:32:29 MSM: 2.2.3 talks about a slightly different thing 15:33:07 ginny has joined #sml 15:33:23 Sandy: not decided yet but personally don't care if you didn't try any of the schemes even if you recognize some 15:33:43 XML_SMLWG(IBM f2f)8:00AM has now started 15:33:50 +Ginny 15:33:51 MSM: this should be a design discussion 15:34:31 MSM: we should come back to this design discussion 15:34:37 ginny, we are dialing in 15:34:42 +[IBM] 15:36:01 specific design question to come back to: do we want to allow / prohibit super-lazy consumers? good-faith consumers? Does a consumer have to try until either something succeeds or until there are no further schemes to try? 15:36:12 John: re differences between validators and consumers : for validator we want to impose rules so that you have a common result 15:36:38 As drafted, this seems to allow consumers to decline to try any of the schemes they support, and treat all references as unresolved. 15:36:47 John: probably don't want to impose the same things for consumers 15:38:38 Kumar; it seems that there are 3 types of consumers: validators, consumers, any 15:39:16 John: consumers obey rule 2.2; validators obey rule 2.1 15:41:36 Why should SML spec care about any other consumers except validators? 15:42:24 pratul has joined #sml 15:42:36 MSM: The description on non-validators in 2.2 doesn't seem to address the case that one of the ref scheme resolve to multiple elements 15:43:16 Sorry, I was earlier logged in as user "sml" 15:43:42 Sandy: 2.2 is the opposite to 2.1 15:45:09 MSM: second quest: I am assuming that 2.1.3 has as a consequence that if I validate right now everything is fine; if I plug out the network, ( after it checks first scheme and before the next ) I get validation errors 15:45:30 Sandy: it is a case not covered 15:46:26 Ginny: with 2.2 two consumers can get two different results 15:46:49 John: that's right, but we are on a different case here 15:47:15 s/2.2/2.1 15:48:37 MSM: yes, schema validator can give different results in the network unplugged scenario but in this case we don't get different results, we get back errors 15:49:36 Sandy: but schema connectivty affects the SML model 15:50:01 MSM: that's true if the definition of the model depends on what's reachable 15:54:30 Pratul: discuss idenity of elements, all related to section 2.1.2 15:54:43 s/idenity/identity 15:55:42 MSM: object identity is subject to negotiations; yes, we need to specify what we understand by object identity 15:56:21 Ginny: same comment as Pratul related to what an object identity refers to 15:56:26 [if we make explicit that these descriptions of the validation process assume / rely on the assumption that all documents in the model are reachable, then item 2.1.3 is not problematic, MSM thinks] 15:56:46 s/MSM: object identity/MSM: document identity/ 15:59:05 Kirk: how do you know that you may get multiple references if deref always returns one element ( this is related to summary item 'If a scheme or multiple schemes resolve to more than one target, make R unresolved.') 15:59:35 Sandy: in this case you should not use the deref implementation 16:01:07 Kumar: we should differentiate between multiple targets and no target 16:01:43 ...both seems to map to unresolved 16:03:38 MSM: we need to make a better system of errors ( what fells under unresolved, as opposed to could not be reached because of network failure, etc ) 16:04:30 Sansy: I don't think this only applies to this issue; the error system should be used in other places in the SML spec 16:04:40 s/Sansy/Sandy/ 16:04:58 John: the agreement seems to be that we need to create this separate set of errors 16:05:28 Sandy: we need to come up with a proposal for the text on how to handle all this cases 16:06:36 Kumar: how do we interpret 2.2.3 ? 16:09:13 MSM: question on how to read 2.1.1, 2.1.2, 2.3; all seems to return errors; are these really errors or unresolved, etc. We need to set on terminology 16:11:05 John: one approach is to take these 'errors' as needing refinment on wheter this should be not known or errors 16:12:07 John: I am confortable as looking at these proposal and reading the trem 'error' as to 'not known' or errors. The fundamentals are correct 16:13:36 action: Sandy to refine this proposal to deal with document not reachable due to network issues 16:13:37 Created ACTION-120 - Refine this proposal to deal with document not reachable due to network issues [on Sandy Gao - due 2007-09-05]. 16:14:51 s/this proposal/proposal on Reference Proposal 16:15:19 s/trem/term 16:17:36 Ginny: can you provide a back-up scheme for the case when first scheme is not reachable over the network ? 16:20:58 MSM: do we have agreement that the consumers should try at least one of the schemes ? 16:23:18 JA: no, the SML semantics a consumer implements may not require any dereferencing of refs at all. MSM: right, I'm persuaded. 16:24:22 John: we asked whether we shold require non-validating consumers to try at least one scheme they recognize. The decision is that this is too strong requirement 16:26:01 one example is one consumer who recognizes only SML references by using sml:ref 16:35:06 [N.B. the final para of section 2 speaks of "an error for cases described in 2.3" -- typo for 2.1, or 2.2, or 2.*.3 ...] 16:42:32 MSM: what is a unit in 'Rationale: it's a unit, because we should not constrain how schemes are defined. ' 16:44:13 John: it says that if someone defines a scheme to allow multiple reference types, it should describe what this means and how a validator should use this data 16:45:05 John: unit = within the same reference you have more than one schemes. That reference is referred to as a unit 16:46:49 Pratul: should we allow a reference having two schemes of the same type ? 16:48:31 John: we should discuss this and understand what to enforce at the schema spec level 16:50:13 Kumar: question about the rationale of dangling ref 16:51:07 ...I see a reference to a model boundary 16:53:24 Sandy: you cannot tell if the reference doesn't exist or cannot be accessed; that's why it was decided to remove the dangling notion and use only unresolved 16:53:31 Sandy has joined #sml 16:54:54 break for lunch 16:57:56 -Ginny 16:57:58 XML_SMLWG(IBM f2f)8:00AM has ended 16:57:59 Attendees were Ginny, SMLF2F 16:58:19 ginny has left #sml 16:58:59 ginny has joined #sml 17:32:16 rrsagent, make log public 17:32:38 rrsagent, generate minutes 17:32:38 I have made the request to generate http://www.w3.org/2007/08/29-sml-minutes.html Sandy 17:35:00 scribe: Kirk 17:35:49 XML_SMLWG(IBM f2f)8:00AM has now started 17:35:56 +[IBM] 17:37:39 pratul has joined #sml 17:38:16 Continuation of topic: How are schemes defined? 17:39:02 Jim: Opened new bug to identify Identity issue. 4992 17:39:44 John: This probably will not be 2nd draft 17:40:35 Pratul: Questions whether this is a topic required for the spec. John &MSM: Yes 17:42:15 Bug has yet to be triaged. Not assigned to draft. 17:42:25 Jordan has joined #sml 17:42:47 zakim, who is here? 17:42:47 On the phone I see SMLF2F 17:42:48 On IRC I see Jordan, pratul, ginny, Sandy, johnarwe, Zakim, Paul, MSM, Marv, Kirk, Valentina, RRSAgent, Jim, trackbot-ng 17:43:13 +Ginny 17:47:16 MSM: Overlapping schemes. Foo scheme (have only foo occurrence) vs. foo-bar scheme, the latter saying you can have two foo schemes. An occurence of one foo scheme can be taken as either one or both. 17:48:27 ...Problem when two instance and validator says not good because it's not foo. This is unacceptable. 17:49:35 ...Consequence of first bullet: you MAY not get satisfactory validation. 17:49:51 In this case, the definition of foo scheme can also specify how it can be reused without casuing the probelm 17:50:31 So in Michael's case the definition of the foo-bar scheme is broken 17:50:51 since it violates the definition of foo scheme 17:53:28 MSM: Validator doesn't know what scheme the occurrence is supposed to be a instance of. 17:54:40 ...So validation is undercut, since there might be another scheme that makes it valid. 17:55:56 Paul has joined #sml 17:56:13 Ginny: Is there a reason to allow overlapping schemes? 17:57:43 John: Not allowing overlap seems to him to be going too far in restricting freedom of definition (e.g., requiring container elements) 17:58:31 Jim: Doesn't spec say scheme element must be child. 17:59:16 MSM: We have an issue against this. It is a restriction that limits schemes--eliminates attribute schemes. 18:00:50 MSM: Validation should assume you know what scheme you want to use. 18:01:44 Paul has joined #sml 18:01:45 ...This situation is like saying, here is a well-formed XML doc, is it valid? Depends upon what schema you use. 18:04:47 ...MSM: you do this with outside information. If you want to use an overlapping scheme, that's your maintenance problem. 18:04:58 Kumar has joined #sml 18:08:00 Consensus appears that there needs to be a hook to tell validator what schemes to use. 18:08:59 There was no formal consensus on the "Validator Hook" issue 18:12:17 Kumar: Case of validator that understands uri-scheme and gets 2-uri schemes, which is not instance of SML ure. 18:14:50 Marv has joined #sml 18:15:31 John: Sandy's version: reference contains exactly 1 one sml URI tag (example of SML URI ref scheme) 18:17:09 ...Kumar's proposal: If reference contains 1 or more tag (and it is an example of SML URI ref scheme) 18:17:26 ...if = 1 tag, then resolve 18:17:37 ...else ERROR 18:20:39 John: Part of validation process, telling validator what schemes to validate. If different schemes, you will get different behavior. 18:21:54 Ginny: Can there be differences in how validators handle overlapping schemes? 18:23:07 John: Scheme definitions include specification of how to recognize scheme. Therefore, this is not a prolem. 18:24:26 NOTE Scheme definitions are a specification on a piece of paper given to programmer. 18:25:34 Ginny: How can you tell if only one instance of tag in Kumar's example? 18:25:53 Sandy: This situation is an instance of both schemes. 18:27:12 Ginny: Example: Have three uri tags: one uri in one scheme, two others in the other? 18:31:38 MSM: if you have a scheme that says "if you see two uri tags, choose one of them and dereference it", i.e. if you have a non-deterministic scheme, then shall we outlaw that? Answer: no need to outlaw it. Your gun, your bullet, your foot. 18:31:41 Sandy: We are taking the entire reference element to try against all your reference rules. (Order does not matter.) 18:34:38 John: We need to either anticipate conflicts of schemes or down stream we must be able to tell validator how to resolve conflicting sets. 18:36:39 Ginny: We need "cautionary notes" in the spec. 18:39:25 Jim: We should not allow the case in which we cannot tell the difference. Not allow case in which your cannot uniquely determine which scheme applies. 18:39:28 I agree with Ginny re the "cautionary Note" 18:41:05 Kumar: I think we are taking on complexity to define corner cases. (Probably unnecessary.) 18:42:33 ..."complexity" = facing situation of not being able to tell or overlapping scheme 18:45:59 MSM: Nothing can prevent overlapping scheme (2 schemes with same tag). We get simplicity in the spec by saying you need to recognize the scheme. If you use overlapping schemes, it is not our responsibility to prevent people from getting into these problems we've been discussing. 18:48:39 Sandy: What Kumar call complexity, Sandy sees this as simplicity. (Kumar: Complexity applies to implementators.) 18:50:30 Jim: We need to "absolve" implementators of need to disambiguating situation in which they can't tell which scheme. 18:51:47 the "xinclude" case is also interesting. it uses attributes. 18:52:18 John: We can recommend what to do; instead of complete "absolution". 18:54:22 MSM: We'll need to set options on validators to turn on and off schemes it know about. 18:56:35 John: Proposal to refine this email 18:57:07 ...Make recommendation against overlapping scheme, but that we can't be prevented, that it needs to be addressed. 18:59:59 Sandy: XInclude: uses an attribute-based scheme. Attributes can overlap with other spec.s. 19:01:01 ...The element itself is the reference vs. our sub-element approach. 19:01:17 johnarwe has joined #sml 19:06:27 -Ginny 19:07:08 How this works: Given an occurrence of scheme, the definition of a scheme does you whether that instance is an instance of this scheme or not. A reference is unresolved only if the instance is evaluated against all schemes and it fits none of them 19:07:13 +??P5 19:07:30 zakim, who is here? 19:07:30 On the phone I see SMLF2F, ??P5 19:07:31 On IRC I see Marv, Kumar, Paul, pratul, ginny, Sandy, Zakim, MSM, Kirk, Valentina, RRSAgent, Jim, trackbot-ng 19:07:36 zakim, P5 is ginny 19:07:36 sorry, ginny, I do not recognize a party named 'P5' 19:07:53 zakim, ??P5 is ginny 19:07:53 +ginny; got it 19:09:45 MSM: Make it more explicit to explain that a scheme that requires 3 uris and gets 6 and says, yes, this is a instance of my scheme; then it is up to the definition of scheme how to dereference the case in which 6 uris are provided. 19:10:10 ...This is an editorial change that should be made. 19:10:52 Final decision: Section 3 needs refinement based on this discussion. 19:11:05 TOPIC: Section 4 19:12:39 Pratul: Second paragraph accords with teleconf. decision. Proposal: To close 4884. 19:13:11 John: Do we have semantic agreement (over syntax agreement)? 19:13:54 Consensus: We need a notion of a null reference 19:16:16 Discussion of use of null reference to represent "This course doesn't have an assistant teacher". MSM: Ok with this. 19:17:44 Consensus: We agree on the semantics of the solution. 19:18:15 John: Syntax should be discussed in email by tomorrow. 19:19:24 John: Does any dissagree with sml:nilref at this time? 19:19:54 All: no objection to this name at this time. 19:21:01 Pratul: We also have consensus in 4780/4795. Is this correct? 19:22:11 Marv has joined #sml 19:22:12 Resolution will be recorded here: targetRequired will be applied to null references. 19:25:42 .. Consensus: .We are getting rid of concept of "empty". 19:28:43 ...Correct 4780: remove references to "empty" and "dangling". 19:30:18 Sandy: Opening issue one issue for removing "empty" and "dangling" references. 19:30:23 BREAK 19:30:46 -ginny 19:46:21 TOPIC: Section 5 19:47:19 Pratul: Agrees with option 2. 19:48:48 +??P5 19:49:02 zakim, ??P5 is ginny 19:49:02 +ginny; got it 19:52:46 MSM: We can retrofit existing vocabularies. What was value of requiring value being fixed? Instance level cannot distinguish between references and non-reference use. 19:53:55 John: Use of GUI tools. No value in saying type level MAY be a reference. 19:54:16 ...Fixed falue is useful for static analysis. 19:57:01 MSM: What depends on calling a type a reference? 19:57:50 ....Response: use of constraints: Acyclic, TargetXXX are defined only for references. 19:59:55 MSM: Fixed is too restrictive for retrofiting existing vocabularies. But MSM needs to think through issues of static analysis and constraints. 20:02:47 MSM/Pratul: only enforce constraints if instance is sml:ref="true". Otherwise, treat instance as null reference. 20:04:43 ...Cannot check constraint (out of going arc) because it may be a null reference or a scheme you do not understand 20:06:34 MSM: Fixed=true doesn't buy you anything. 20:08:23 Valentina has joined #sml 20:09:26 MSM: Discussion of arcs needs to be clarified for null references. 20:09:47 Jim: Section also implies that the instance is the arc. This needs to be clarified. 20:11:02 Valentina has joined #sml 20:11:10 MSM: Constraints are enforceable only if reference is NOT nil, so fixed-"true" does not buy you anything. 20:12:48 TargetRequired issue 20:13:21 Pratul: Define it to say that ??? 20:14:23 rrsagent, draft minutes 20:14:23 I have made the request to generate http://www.w3.org/2007/08/29-sml-minutes.html Valentina 20:14:49 We can choose to define targetXXX constrainst as enforced only on instances for which sml:ref="true" if we decide that sml:ref is an optional attribute for reference types 20:17:26 John: Value of not having fixed="true" (going from MUST to MAY) is able to have new references for existing vocabulary and still preserve original vocabulary. 20:18:00 MSM: Fixed="true" does not buy you anything for the GUI. 20:23:46 Sandy: Only issue in our specs is, Where do we put the constraint attributes? Allowed only where fixed="true". 20:29:54 MSM: Concepts in existing vocabulary may not map into SML semantics of reference. Fixed="true" made this impossible. We could not represent reference semantics in existing vocabularies. 20:36:23 ...We cannot map from a more precise vocabulary (superset or overlapping set) to a general vocabulary without the loss of semantics. Fixed="true" makes it impossible to do the mapping. 20:36:49 ...This is an example of the problem of Architectural Forms. 20:55:37 Discussion of the issue. John explains this issue by using multiple inheritance. There is a need to introduce a new type to say that a subset of an original type are sml references if it is done with fixed="true". 21:00:56 ..."Price of entry" to make the distinguish between ref and non-ref instance of the type: add sml:ref=true. If a new type is must be identified, there are also metadata changes. 21:02:58 Valentina has joined #sml 21:04:42 ...Approach of MSM does not prevent static analysis. 21:08:05 ...Some types can fix its value to true, and this supports static analysis. But does not preclude other types for not fixing value to true. 21:08:41 MSM: On what types can we impose the contraints? 21:09:02 ....some types always have sml:ref="true" 21:09:13 ...some type never have sml:ref="true" 21:09:30 ...some types May have sml:ref="true" 21:09:47 ... some have it explicitly 21:11:22 ... some have it by extension wildcard) 21:12:25 MSM: For the always case: you still have to check for null, not too much more expensive for sml:ref=true. 21:13:36 Kumar: Does sufficient value in Option 2 that we should go to Option 3? 21:17:14 We can keep sml:refType to get the fixed value and apply constraints. 21:17:33 Paul has joined #sml 21:22:02 MSM: Possible solution for applying constraints: always and MAY (explicitly) 21:22:59 ...Kumar's question: include MAY (wc) as well. 21:39:42 Issue: for option 3: where can the constraints be written. Reminder: these are attributes in the schema. 21:50:55 We can specify the constraints on any complex type and they have meaning only for those instances with sml:ref="true". If not specified on the complexType, there is nothing to check. 21:53:19 ...Constraints apply one to defined complex types with attribute extensibility. Or, the sml:ref="true" as required and fixed="true". 21:56:53 Jim: We might want to add constraints to an abstract or parent type in order to say that all subtypes is acyclic. MSM: Great idea! 21:59:42 MSM: All situations for applying constraints (above table) are encomposed by this solution!! 22:03:26 acyclic and targetXXX are only allowed in (5 options): 22:03:36 1. types derived from refType and elements with those types 22:03:58 2. types with sml:ref + required + fixed=true 22:04:15 3. types with explicit reference to sml:ref, allowing either true or false value 22:04:53 4. types that allow sml:ref attribute, allowing true or false, via wildcard or explicit reference 22:05:01 Consensus in Room: This is agreed upon. sml:RefType is gone. Recognize instances using following rule: 22:05:07 5. no restriction. they can be specified on any element or type. 22:05:32 ...any element instance with sml:ref="true" 22:05:46 ...Wjem cam S<: ref Cpmstraomts be s[ecofeod 22:06:40 Option 4: 22:06:40 - sml:refType is gone. 22:06:40 - any element instance with sml:ref='true' is an sml reference. 22:06:40 (already so in part 1 of the working paper) 22:06:42 - Q. which type definitions may carry constraints like sml:acyclic? 22:06:45 A. Any type definition at all. (We CANNOT require that sml:ref 22:06:47 be allowed explicitly or by wildcard, because of Jim's point.) 22:06:50 Those constraints are enforced on the set of instances of that 22:06:52 type definition which are in fact SML references. 22:06:59 s/Any type definition/Any complex type definition/ 22:08:46 Ginny: This sounds good 22:08:53 WE HAVE CONSENSUS!!! 22:09:33 /msg MSM thank you! 22:09:59 Sandy: Two additional questions 22:13:35 ...1. Use key ref but XPath does not point to a key? How does deref work? 22:14:32 ... MSM: handle in deref. An element that is not a reference refers to nothing. Return nothing. (We may want to revisit this with XPath 2) 22:16:17 ... We have Consensus on this answer. 22:17:56 ...2. Schema has default for sml:ref="true" in the PVSI. 22:19:48 ... Pratul: This is not a reference according to our spec. PSVI is not required. 22:20:18 ... Kumar: But the requirement is not that PVSI should be ignored. 22:20:55 ... MSM: If you use the PSVI and I don't, this is a serious interop problem. 22:28:57 ... Kumar text must say not to look at PSVI. 22:32:34 ... Kumar: problem where sml:ref="True" in a parent type of the subtype of which the instance is an instance. 22:34:27 Marv has joined #sml 22:35:02 Sandy: understand all the concerns; but there is a nice application. 22:35:32 Sandy: with support for schema default of sml:ref, then there is no need to change existing documents by adding sml:ref to make them SML documents. 22:35:55 Kumar: there is not really an interop problem in allowing the PSVI to be consulted. 22:36:08 Sandy: e.g. if I have thoughts of XInclude documents, I can simply write a schema that provides sml:ref=true to elements and now they are suddenly sml refs. 22:36:25 There is no interop problem for sml model validators, because they all must do schema validation 22:36:32 s/thoughts/thousands 22:37:10 Kumar: and the interop problem for non-validating consumers is no bigger than the one we already have thanks to things like scheme support 22:37:15 s/suddenly sml refs./suddenly sml refs, without the need to modify those instance documents. 22:37:35 Adjourning: 6:40 22:37:46 -ginny 22:37:49 rrsagent, generate minutes 22:37:49 I have made the request to generate http://www.w3.org/2007/08/29-sml-minutes.html Kirk 22:37:50 -SMLF2F 22:37:51 XML_SMLWG(IBM f2f)8:00AM has ended 22:37:53 Attendees were SMLF2F, Ginny 22:38:03 /quit 22:38:05 ginny has left #sml 22:38:41 Jim has left #sml 22:38:51 d 22:39:16 MSM: should also ignore DTD defaulted sml:ref attributes, because there's no guaranteed interop. some processor may not read attribute decls from external DTDs. 22:41:45 rrsagent, generate minutes 22:41:45 I have made the request to generate http://www.w3.org/2007/08/29-sml-minutes.html Sandy 23:04:07 Zakim has left #sml