RE: [xml-dev] Were these derived from a logical data model: XSLT, XML Sc

["Costello, Roger L." <costello@mitre.org>]

Liam Quin wrote:

> XSLT 2 is built on a logical data model, although 
> not one described in terms of relational algebra.

Thanks Liam.  

I took a look at the XPath Data Model [1].  It's all prose.  There are
no UML-type diagrams.

In fact, I can't find any documents on XSLT, XML Schema, XHTML, or
Schematron that contain UML- or ER-type diagrams.  The documents are
all prose.  The prose defines and describes concepts at an abstract
(infoset) level.

As far as I can tell, the "logical data model" used to create an XML
vocabulary is different than the "logical data model" used to create a
database- or object-system.

Here are the differences that I see:

Creating a database or object system involves:  
   . create UML- or ER-type diagrams, and then 
   . create the database or object system directly 
     from those diagrams.  

Conversely, creating an XML vocabulary involves: 
   . define and describe in prose the concepts 
     at an abstract (infoset) level, and then 
   . create a specification from that prose, and then 
   . create an XML Schema or DTD or Relax NG schema.  

Do you agree?

/Roger

[1] http://www.w3.org/TR/xpath-datamodel/#dt-instance