# Base: http://bblfish.net/work/atom-owl/2004-08-12/
@prefix xsd:     <http://www.w3.org/2001/XMLSchema#> .
@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix foaf:    <http://xmlns.com/foaf/0.1/> .
@prefix :        <http://bblfish.net/work/atom-owl/2004-08-12/Atom.owl#> .

<http://bblfish.net/work/atom-owl/2004-08-12/entry.2004-08-13-1632.n3>
      a       :Entry ;
      :alternate
              [ a       :Link ;
                :href   <http://bblfish.net/work/atom-owl/2004-08-12/blogexample.html#entry.2004-08-13-1632.n3> ;
                :mime-type "text/html"^^xsd:string ;
                :text   "html blog entry"^^xsd:string
              ] ;
      :author [ a       foaf:Person ;
                foaf:homepage <http://bblfish.net/> ;
                foaf:mbox <mailto:hjs@bblfish.net> ;
                foaf:name "H. Story"^^xsd:string
              ] ;
      :content
              [ a       :Content ;
                :data   "Let me illustrate two views on an Entry graphically, so as not to have to take any sides among the many possible serialisations of semantic web triples: N3, N-Triples, RDF, ... Each of these serialisation formats can be mapped onto a graph of triples, as explained in the w3c's <a href='http://www.w3.org/TR/rdf-mt/'>RDF Semantics</a> paper. I here represent resources in rounded rectangles, blank nodes by circles, Literals by rectangles, and of course predicates by named arrows.<p> Let us start off with a simple graphical representation of an Entry written in a file  <code>entry1.n3</code>, written by Karl Dubost, where he asserts the cryptic '2b v not2b'. <br><img src='Atom-FOAF-ExampleEntry-1.jpg'><br> The <code>id</code> of the entry is <code>tag:e1</code>, and it is the first version as hinted at by the  <code>entry-version</code> which is <code>tag:e1#v1</code>. The entry was created on 11 Jun 2002 at 5pm, and was published (<code>issued</code>) shortly thereafter, at 10 minutes past 5. (Note that since we know that the entry is written by Karl Dubost, we may be able to find who is friends are if we have access to some FOAF files that mention him.)<p> Perhaps shortly later Karl finds that he wants to make a change to his entry. He prefers titles to start with capitals, and changes his statement to a question. He is still thinking about this change, so this change does not yet have a publication date. (how we got this file is of course a problem for my story now). As a result the graph we have is as follows:<br><img src='Atom-FOAF-ExampleEntry-2.jpg'><br> Here I have highlighted in green the changes to the graph. Gone is the issued field, a modified date has appeared, and the data fields of the title and entry fields have slightly changed. Of course we have a new version id.<p> Any person who fetches  <code>entry1.n3</code> after the change (and after he issues it) will not be able to retrieve the original version,  as it will have been completely replaced by the new one. They will know when the file was last modified though. But if someone were to keep track of all these changes - either the editor that Karl is using in order to allow him to backtrack to previous versions were he to think he had made a mistake, or some agregator that wanted to keep a fuller view of the changes made to the posts on Karl's web site (perhaps in order to notify the aggregator's owner that a reply he wrote to Ken's post had changed) - then he would presumably want to keep the changes stored in its local database by organising the entries by EntryID, in  a database similar to our <a href='AllInOneDatabase.n3'>AllInOneDatabase.n3</a>. The graph for this entry would then look like this:<br><img src='Atom-FOAF-ExampleEntry-3.jpg'><br> Here the root of the tree is the <code>EntryID</code>, which points to the two <code>EntryVersion</code>s. Notice that in this case the <code>EntryVersion</code>s have an <code>entry-location</code>, to help find the original entry file. The location is not attached to the <code>EntryID</code> as the location of an Entry could change over time. In this case  the entry has remained in the same position.<p> It should be very easy to specify a logical relation allowing one to deduce one of the views from the other.  Since we are speaking in ontology, there is not concptual priority of one of these views over the other. They both exist simultaneously."^^xsd:string ;
                :mime-type "text/html"^^xsd:string
              ] ;
      :copyright <http://creativecommons.org/licenses/by-sa/2.0/> ;
      :created "2004-08-13T16:32:00+0200"^^xsd:dateTime ;
      :entry-version <tag:bblfish.net/20040813/1632/blog1#version1> ;
      :id     <tag:bblfish.net/20040813/1632/blog1> ;
      :in-reply-to <tag:bblfish.net/20040813/1445/blog1#version1> ;
      :title  [ a       :Content ;
                :data   "Graphical illustration of the two pespectives"^^xsd:string ;
                :mime-type "text/simple"^^xsd:string
              ] .

<tag:bblfish.net/20040813/1445/blog1#version1>
      :entry-location <http://bblfish.net/work/atom-owl/2004-08-12/entry.2004-08-13-1445.n3> .