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general review of NF&R

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Mon, 30 Mar 2009 19:51:23 -0400 (EDT)
Message-Id: <20090330.195123.234596867.pfps@research.bell-labs.com>
To: public-owl-wg@w3.org
Review of NF&R


General Comments:

1: NF&R is becoming too much for too many things.  I would much prefer a
cut-down version that concentrates on what NF&R is supposed to be - an
overview of the new stuff in OWL 2 as related to the use cases and other
rationale that the WG has identified.  I actually don't mind the overall
organization of NF&R, just its length.

2: There are quite a few changes needed to fix grammatical and wording
problems in the document and to reduce the amount of unneeded prose.  I
have made detailed edits up to Section 2.2.2 on my paper copy of the
document and can apply them to the document if it is so desired.  

Here is my changed version of the start of Section 2:

*******************************************************
== Features & Rationale ==

OWL 2 is an update to OWL adding several new features, including
increased expressive power for properties, extended support
for datatypes, simple metamodeling capabilities, extended annotation
capabilities, and keys. OWL 2 also defines several profiles &ndash;
OWL 2 language subsets that may better meet certain performance
requirements or may be easier to implement. The new OWL 2 features
are presented here, organized in the following categories:  

# syntactic sugar to make some common statements easier to say, 
# new constructs that increase expressivity, 
# extended support for datatypes, 
# simple metamodeling capabilities,
# extended annotation capabilities, and
# other innovations.

Each feature is described in a common pattern as follows:  
* a brief sentence explaining why the new feature was added,
* a feature description including a informal meaning, informal syntax, and a simple example issued from Use Cases,
* the theoretical and implementation implications of the new feature, and
* links to related use cases.

=== Syntactic sugar === 	

OWL 2 adds syntactic sugar to make some common patterns easier to write. 

==== F1: [http://www.w3.org/2007/OWL/wiki/Syntax#Disjoint_Union_of_Class_Expressions DisjointUnion]==== 

While OWL 1 provides means to define a set of subclasses as a disjoint
and complete covering of a superclass by using several axioms, this
cannot be done concisely. 
<span class="nonterminal">DisjointUnion</span> defines a class as the
union of other classes, all of which are pairwise disjoint. It is a
shorthand for owl:disjointWith statements used in combination with
owl:unionOf to define a complete superclass from a set of mutually
disjoint subclasses. 
[[http://www.w3.org/2007/OWL/wiki/Syntax#Disjoint_Union_of_Class_Expressions Normative Syntax]] 
[[http://www.w3.org/2007/OWL/wiki/Direct_Semantics#Class_Expression_Axioms Direct Semantics]]
[[http://www.w3.org/2007/OWL/wiki/RDF-Based_Semantics#Semantic_Conditions_for_Equivalence_and_Disjointness_Axioms RDF-Based Semantics]]

<div class="grammar">
<span class="nonterminal">DisjointUnion</span> <span class="name">({ A } C CE<sub>1</sub> ... CE<sub>n</sub> )</span> where <span class="name">C</span> is a class,  <span class="name">CE<sub>i</sub></span>, 1 &le; i &le; n are class expressions, and { A }  zero or more annotations.
</div>

<div class="anexample">
* HCLS
<div class="axioms">
{| class="axioms"
|-
| class="name" | DisjointUnion(''BrainHemisphere'' ''LeftHemisphere'' ''RightHemisphere'' ) (''UC#2'')
| A ''BrainHemisphere'' is exclusively either a ''LeftHemisphere'' or a ''RightHemisphere'' and cannot be both a ''RightHemisphere'' and a ''LeftHemisphere''.
|-
|''-- RDF --''
|
|-
| ''BrainHemisphere'' ''owl:disjointUnionOf'' ( ''LeftHemisphere'' ''RightHemisphere'' )
| 
|-
|''-------''
|
|-
| class="name" | DisjointUnion(''Lobe''  ''FrontalLobe''  ''ParietalLobe''  ''TemporalLobe''  ''OccipitalLobe'' ''LimbicLobe'') (''UC#1'')
| A ''Lobe'' is exclusively either a ''FrontalLobe'' , a ''ParietalLobe'', a  ''TemporalLobe'', a ''OccipitalLobe'' or a ''LimbicLobe'' and cannot be both of them.
|-
| class="name" | DisjointUnion(''AmineGroup'' ''PrimaryAmineGroup'' ''SecondaryAmineGroup'' ''TertiaryAmineGroup'' ) (''UC#3'')
|An ''AmineGroup'' is exclusively either a ''PrimaryAmineGroup'', a ''SecondaryAmineGroup'' or a ''TertiaryAmineGroup'' and cannot be both of them. 
|-
|}
</div>
	
* Automotive industry

<div class="axioms">
{| class="axioms"
|-
| class="name" | DisjointUnion(CarDoor FrontDoor RearDoor TrunkDoor) (''UC#4'')
| A ''CarDoor'' is exclusively either a ''FrontDoor'', a ''RearDoor'' or a''TrunkDoor'' and not both of them.
|-
|}
</div>
</div>

Since <span class="name">DisjointUnion</span> is simply a shorthand for
several ''disjointWith'' statements in combination with unionOf, it does
not change the expressiveness, semantics, or complexity of the language.
Implementations, however, may prefer to take special notice of
DisjointUnion for more efficient processing.

[[#Use_Case_.231_-_Brain_image_annotation_for_neurosurgery_.5BHCLS.5D|Use Case #1]] [[#Use_Case_.232_.E2.80.93_The_Foundational_Model_of_Anatomy_.5BHCLS.5D|Use Case #2]] [[#Use_Case_.233_-_Classification_of_chemical_compounds_.5BHCLS.5D|Use Case #3]] [[#Use_Case_.234_-_Querying_multiple_sources_in_an_automotive_company_.5BAutomotive.5D|Use Case #4]]'''

*******************************************************



Changes:

0/ Abstract

  OWL 2 provides new features over the previous version of OWL.  This
  document provides a description of these new features and other design
  choices that went into OWL 2, along with their rationale, based on use
  cases provided to the W3C OWL Working Group.

1/ Introduction

  This document provides brief overviews of the main new features of OWL
  2 and their rationale. These language features were determined based
  on real applications and user and tool-developer experience, some of
  which has been documented in the OWLED Workshop Series [...].  The
  inclusion of the features are supported by use cases provided to the
  W3C OWL Working Group, which are listed in an appendix.

  This document also describes and motivates some of the other design
  decisions that were made during the development of OWL 2 or
  purposefully retained from OWL 1, particularly the various concrete
  syntaxes for OWL 2, and the relationship of OWL 2 with RDF.

  OWL 2 extends the previous OWL Web Ontology Language (OWL 1) [OWL ??]
  and inherits the language features, design decisions, and use cases
  for OWL 1.  This document thus forms an extension of the Use Cases and
  Requirements that underlie OWL 1 [OWL Use Cases and Requirements].

Remove the last paragraph of the introduction.  It is not needed.

2/ Features and Rationale

There is no need for the "Feature", ... tags.

Changes similar to those above should be made throughout Section 2.

3/ Other Design Choices and Rational

This section should also be slimmed down.

4/ Illustrative Use Cases

4.1/ 

This subsection only repeats information in Section 2, and should be
removed.

4.2/

Why are some features given by name and others by number?  This should
be made consistent.  The legend is also unnecessary, as the information
is in Section 2.
Received on Monday, 30 March 2009 23:49:41 GMT

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