Comments on: Standards Words http://www.robweir.com/blog/2008/05/standards-words.html Thinking the unthinkable, pondering the imponderable, effing the ineffable and scruting the inscrutable Tue, 16 Mar 2010 03:07:49 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: Rob http://www.robweir.com/blog/2008/05/standards-words.html#comment-1912 Rob Fri, 09 May 2008 22:07:00 +0000 http://www.robweir.com/blog/2008/05/standards-words.html#comment-1912 Sidney, there is nothing stated in the Relax NG specification that answers your question. Nothing is stated that would give the expectation that the word 'set' is used in a strict Cantorian sense either.<br/><br/>But note that a set does not need to be computable in order to test membership. For example, take the set consisting of the following numbers:<br/><br/>1,2,3, the number of regular season wins for the Red Sox in 2008, and the number of twin primes.<br/><br/>Is 1 a member of the set? Yes, obviously. <br/><br/>Is 95 a member of the set? This is unknown. 95 is not one of the integers explicitly included. And we know that there are far more than 95 twin primes. But we will not know until the season ends whether the Red Sox will win exactly 95 games.<br/><br/>Is 5 a member of the set? No. We can say that with certainty, because we know that the Red Sox have already won 23 games so far this season, and there are more than 5 twin primes. Sidney, there is nothing stated in the Relax NG specification that answers your question. Nothing is stated that would give the expectation that the word ’set’ is used in a strict Cantorian sense either.

But note that a set does not need to be computable in order to test membership. For example, take the set consisting of the following numbers:

1,2,3, the number of regular season wins for the Red Sox in 2008, and the number of twin primes.

Is 1 a member of the set? Yes, obviously.

Is 95 a member of the set? This is unknown. 95 is not one of the integers explicitly included. And we know that there are far more than 95 twin primes. But we will not know until the season ends whether the Red Sox will win exactly 95 games.

Is 5 a member of the set? No. We can say that with certainty, because we know that the Red Sox have already won 23 games so far this season, and there are more than 5 twin primes.

]]> By: sidney http://www.robweir.com/blog/2008/05/standards-words.html#comment-1906 sidney Thu, 08 May 2008 07:32:00 +0000 http://www.robweir.com/blog/2008/05/standards-words.html#comment-1906 Rob, the definition you give for "validity" is the one that leaves the most room for variation, and it also seems to be the key point of disagreement between you and Alex regarding validation of ODF documents. You quote Relax NG 3.25 "a member of the set of XML documents described by the schema". Alex says that by definition if membership in the set is not computable then "there is no set" to validate against. That's the crux, and the question I would have for Alex is if there is some specification that says that the set must be computable, or is he basing his assertion on common sense. If the latter, perhaps it seems like common sense that a set is not a set if you can't decide if something is or is not a member of the set. But computability theory defines and works with computable sets, recursively enumerable sets, and noncomputable sets. There is no fundamental reason to reject the latter two out of hand. So it comes down to the question of whether there is a definition of "validity" in some formal specification that applies to ODF that does specify constraints on the computability of the set of valid documents. Rob, the definition you give for “validity” is the one that leaves the most room for variation, and it also seems to be the key point of disagreement between you and Alex regarding validation of ODF documents. You quote Relax NG 3.25 “a member of the set of XML documents described by the schema”. Alex says that by definition if membership in the set is not computable then “there is no set” to validate against. That’s the crux, and the question I would have for Alex is if there is some specification that says that the set must be computable, or is he basing his assertion on common sense. If the latter, perhaps it seems like common sense that a set is not a set if you can’t decide if something is or is not a member of the set. But computability theory defines and works with computable sets, recursively enumerable sets, and noncomputable sets. There is no fundamental reason to reject the latter two out of hand. So it comes down to the question of whether there is a definition of “validity” in some formal specification that applies to ODF that does specify constraints on the computability of the set of valid documents.

]]> By: orcmid http://www.robweir.com/blog/2008/05/standards-words.html#comment-1899 orcmid Wed, 07 May 2008 19:09:00 +0000 http://www.robweir.com/blog/2008/05/standards-words.html#comment-1899 @rob: I was thinking of the "validity" of instance documents, not of the schema itself as a document.<br/><br/>I notice that the XML 1.0 "validity constraints" do address the validity of a document type declaration (DTD) as well as the validity of XML 1.0 documents and the document type declarations, if any, that apply to them. <br/><br/>But I was sticking to teasing out "validity" with respect to document instances (not their schemas) and how schema-validity assessment is used in that context (for XML Schema, at least).<br/><br/>To sharpen my question: What is the language of the Relax NG specification with regard to what is said about a document that accepted by a proper validator using a particular (valid?) Relax NG Schema. <br/><br/>If there is some sort of validation condition on Relax NG Schemas themselves, what is that called, and does it involve more than the schema being accepted by a Relax NG Validator applying the Relax NG Schema?<br/><br/>[Yes, I am being lazy. I am not sure I have my hands on the correct Relax NG spec. This seems like an useful conversation and clarification in any case. I have to dig into this for my nfoWorks project eventually, but just not yet.] @rob: I was thinking of the “validity” of instance documents, not of the schema itself as a document.

I notice that the XML 1.0 “validity constraints” do address the validity of a document type declaration (DTD) as well as the validity of XML 1.0 documents and the document type declarations, if any, that apply to them.

But I was sticking to teasing out “validity” with respect to document instances (not their schemas) and how schema-validity assessment is used in that context (for XML Schema, at least).

To sharpen my question: What is the language of the Relax NG specification with regard to what is said about a document that accepted by a proper validator using a particular (valid?) Relax NG Schema.

If there is some sort of validation condition on Relax NG Schemas themselves, what is that called, and does it involve more than the schema being accepted by a Relax NG Validator applying the Relax NG Schema?

[Yes, I am being lazy. I am not sure I have my hands on the correct Relax NG spec. This seems like an useful conversation and clarification in any case. I have to dig into this for my nfoWorks project eventually, but just not yet.]

]]> By: Stephen http://www.robweir.com/blog/2008/05/standards-words.html#comment-1898 Stephen Wed, 07 May 2008 18:10:00 +0000 http://www.robweir.com/blog/2008/05/standards-words.html#comment-1898 http://www.askoxford.com/concise_oed/shall?view=uk<br/><i>"Strictly speaking shall should be used with I and we to form the future tense, as in I shall be late, while will should be used with you, he, she, it, and they, as in she will not be there. This, however, is reversed when strong determination is being expressed, as in I will not tolerate this , and you shall go to school. In speech the distinction tends to be obscured, through the use of the contracted forms I’ll, she’ll, etc"</i> http://www.askoxford.com/concise_oed/shall?view=uk
“Strictly speaking shall should be used with I and we to form the future tense, as in I shall be late, while will should be used with you, he, she, it, and they, as in she will not be there. This, however, is reversed when strong determination is being expressed, as in I will not tolerate this , and you shall go to school. In speech the distinction tends to be obscured, through the use of the contracted forms I’ll, she’ll, etc”

]]> By: Nate http://www.robweir.com/blog/2008/05/standards-words.html#comment-1896 Nate Wed, 07 May 2008 11:45:00 +0000 http://www.robweir.com/blog/2008/05/standards-words.html#comment-1896 I think it might also be useful to define some elements of intent, don't you think?<br/><br/>For instance, to the extent that OO.o, Google Docs, and IBM Symphony product documents with ODF file extensions that are not perfectly conformant to the ODF 1.1 specification, what is the intent? Are these bugs in the software that must be reported and fixed? And does this mean that when any of those platforms produce files with ODF extensions that ARE conformant, that they developers are complying with the spec?<br/><br/>Similarly, looking Office 2007's OOXML output and comparing it to the DIS29500 spec -- you can't even call non-conformance a bug, can you? The developers of Office 2007 weren't trying to adhere to that specification because it didn't exist yet (and still doesn't.) At such time as the spec actually exists, and Microsoft releases a version that claims to write it, then there's something to be evaluated on whether the software has a bug.<br/><br/>I say this because Alex's "smoke tests" have been for the most part mystifying to me. What's he trying to test? Whether it's possible to get output matching a spec that doesn't exist yet from a product released 18 months ago? Whether it's possible to get output from one piece of software that isn't conformant to a given output format? Whether OO.o has bugs? Whether Office 2007 has bugs?<br/><br/>This is software. They both have bugs. Was that ever in question? I think it might also be useful to define some elements of intent, don’t you think?

For instance, to the extent that OO.o, Google Docs, and IBM Symphony product documents with ODF file extensions that are not perfectly conformant to the ODF 1.1 specification, what is the intent? Are these bugs in the software that must be reported and fixed? And does this mean that when any of those platforms produce files with ODF extensions that ARE conformant, that they developers are complying with the spec?

Similarly, looking Office 2007’s OOXML output and comparing it to the DIS29500 spec — you can’t even call non-conformance a bug, can you? The developers of Office 2007 weren’t trying to adhere to that specification because it didn’t exist yet (and still doesn’t.) At such time as the spec actually exists, and Microsoft releases a version that claims to write it, then there’s something to be evaluated on whether the software has a bug.

I say this because Alex’s “smoke tests” have been for the most part mystifying to me. What’s he trying to test? Whether it’s possible to get output matching a spec that doesn’t exist yet from a product released 18 months ago? Whether it’s possible to get output from one piece of software that isn’t conformant to a given output format? Whether OO.o has bugs? Whether Office 2007 has bugs?

This is software. They both have bugs. Was that ever in question?

]]> By: Rob http://www.robweir.com/blog/2008/05/standards-words.html#comment-1894 Rob Wed, 07 May 2008 03:20:00 +0000 http://www.robweir.com/blog/2008/05/standards-words.html#comment-1894 Are you talking about conformance of a schema file itself to the underlying schema definition language?<br/><br/>Relax NG defines conformance for validators. It does not define conformance of schemas. Of course Relax NG has a schema for itself, a Relax NG schema, of course. The ODF 1.0 schema is valid Relax NG, relative to the Relax NG schema. Are you talking about conformance of a schema file itself to the underlying schema definition language?

Relax NG defines conformance for validators. It does not define conformance of schemas. Of course Relax NG has a schema for itself, a Relax NG schema, of course. The ODF 1.0 schema is valid Relax NG, relative to the Relax NG schema.

]]> By: orcmid http://www.robweir.com/blog/2008/05/standards-words.html#comment-1889 orcmid Tue, 06 May 2008 21:09:00 +0000 http://www.robweir.com/blog/2008/05/standards-words.html#comment-1889 I like your approach here, and the separation of conformance and compliance is very useful.<br/><br/>When I saw the exchanges between you and Alex Brown on "validity" something kept nagging at me about how validity applies with respect to XML Schema. (I notice you point out that different notions apply to different schema schemes, but then I wonder what it means when multiple flavors are provided or schema translations are used.]<br/><br/>First, I notice that XML 1.0 has been pretty consistent about validity of documents and it is related to the presence of a DTD for the most part. There are "validity constraints" throughout the XML specification (e.g., section 3.1.1) and while they can all be considered syntactical/grammatical rules, they go beyond treating the DTD solely as a grammar of the context-free variety. <br/><br/>Without getting into how different schema systems might grandfather some of those constraints, absent any document type declaration, I revisited the XML Schema specification and found what had been nagging at me.<br/><br/>In the specification of XML Schema, there is great care to speak of schema [relative] validation of XML instance documents. The suggestion of document validity is avoided. There is also a preference for "schema-validity assessment" [Section 2.1 of XML Schema Part 1: Structures].<br/><br/>Is Relax NG any different? I like your approach here, and the separation of conformance and compliance is very useful.

When I saw the exchanges between you and Alex Brown on “validity” something kept nagging at me about how validity applies with respect to XML Schema. (I notice you point out that different notions apply to different schema schemes, but then I wonder what it means when multiple flavors are provided or schema translations are used.]

First, I notice that XML 1.0 has been pretty consistent about validity of documents and it is related to the presence of a DTD for the most part. There are “validity constraints” throughout the XML specification (e.g., section 3.1.1) and while they can all be considered syntactical/grammatical rules, they go beyond treating the DTD solely as a grammar of the context-free variety.

Without getting into how different schema systems might grandfather some of those constraints, absent any document type declaration, I revisited the XML Schema specification and found what had been nagging at me.

In the specification of XML Schema, there is great care to speak of schema [relative] validation of XML instance documents. The suggestion of document validity is avoided. There is also a preference for “schema-validity assessment” [Section 2.1 of XML Schema Part 1: Structures].

Is Relax NG any different?

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