--- a/primer/Primer.html	Tue Oct 18 18:41:22 2011 +0100
+++ b/primer/Primer.html	Wed Oct 19 15:33:23 2011 +0100
@@ -138,13 +138,38 @@
    <section>
     <h3>Entities</h3>
 
-    <p>An intuitive overview of how to think about entities and their characterising attributes in Prov-DM.</p>
+    <p>
+     In Prov-DM, the things that you ask the provenance of are called <i>entities</i>,
+     and one entity may have many others in the description of its provenance, e.g. the
+     provenance of a building could include the stones that formed its bricks and the
+     spades that dug its foundations. In contrast to process executions, below, entities
+     are understood by their states rather than the activities they perform.
+    </p>
+    <p>
+     Each thing in the world can be viewed from different perspectives and, given that
+     the provenance of one entity may be composed from assertions made by multiple parties,
+     there must be care that the entity referred to by one party is the same as for another.
+     For example, a document D may have document ID 123 throughout its existence, but
+     the first version of the document Dv1 is in HTML 4.0, while the next version, Dv2,
+     is in XHTML 1.1. If one party, describing D, asserts that the document has ID 123, but
+     then another asserter, looking at Dv2, adds that the document is in XHTML 1.1, then
+     there is ambiguity: did the document have ID 123 and was it in XHTML 1.1 throughout its
+     lifetime or just in one version? We have to characterize each entity in Prov-DM data
+     by stating the attributes that define it, e.g. D is defined by its ID being 123, while Dv2 is
+     defined by its ID being 123 <i>and</i> its version being 2.
+    </p>
    </section>
 
    <section>
     <h3>Process Executions</h3>
 
-    <p>An intuitive overview of how to think about provenance executions in Prov-DM.</p>
+    <p>
+     A Prov-DM process execution is an activity that has occurred. Most importantly,
+     process executions are how entities come into existence, often making use of
+     existing entities to achieve this. Continuing the example from above, document Dv2
+     was generated by a translation from HTML 4.0 to XHTML 1.1 that makes use of document Dv1,
+     and this translation activity is a process execution.
+    </p>
    </section>
 
    <section>
@@ -184,7 +209,7 @@
     particular when entities are asserted by different <em>accounts</em> or over
     different time periods. If two such entities have <em>overlapping
     lifespans</em>, and the first entity have some <em>attributes</em> that
-    have not been asserted (and not neccessarily always true) for the second entity,
+    have not been asserted (and not necessarily always true) for the second entity,
     then the first entity is said to be <em>complementing</em> the second
     entity, that is the first entity helps form a more detailed
     description of the second entity, at least for the duration of the
@@ -270,10 +295,10 @@
      Betty retrieves the provenance of the chart, to determine from where the facts presented derive.
     </p>
     <p>The Prov data includes the assertions:</p>
-    <blockquote>
-     ex1:chart1 a prov:Entity .<br/>
-     ex1:dataSet1 a prov:Entity .<br/>
-    </blockquote>
+    <pre class="turtle example">
+     ex1:chart1   a prov:Entity .
+     ex1:dataSet1 a prov:Entity .
+    </pre>
     <p>These statements, in order, assert that the chart (ex1:chart1)
      is an entity, the data set (ex1:dataSet1) is an entity.</p>
 
@@ -285,9 +310,9 @@
     <p>Further, the Prov data asserts that there was
      a process execution (ex1:compiled) denoting the compilation of the
      chart from the data set</p>
-    <blockquote>
-     ex1:compiled a prov:ProcessExecution .<br/>
-    </blockquote>
+    <pre class="turtle example">
+     ex1:compiled a prov:ProcessExecution .
+    </pre>
    </section>
 
    <section>
@@ -297,11 +322,11 @@
      process, the compilation process made use of GovData, and the chart was
      derived from the data set (more on derivation below).</p>
 
-    <blockquote>
-     ex1:chart1 prov:wasGeneratedBy ex1:compiled .<br/>
-     ex1:compiled prov:used ex1:dataSet1 .<br/>
-     ex1:chart1 prov:wasDerivedFrom ex1:dataSet1 .<br/>
-    </blockquote>
+    <pre class="turtle example">
+     ex1:chart1   prov:wasGeneratedBy ex1:compiled .
+     ex1:compiled prov:used           ex1:dataSet1 .
+     ex1:chart1   prov:wasDerivedFrom ex1:dataSet1 .
+    </pre>
 
     <p>From this information Betty can see that
      the mistake could have been in the original data set or else was introduced