updated Drools docs content from SOA 4.2.CP03 Rules Guide

I revised the language of the "Insertion" section while fixing a couple of reported grammatical errors for the 4.2.CP03 SOA Rules Guide.

The original language is the same in: http://anonsvn.jboss.org/repos/labs/labs/jbossrules/soa_tags/4.3.0.FP01_BRMS_5.0.EA/drools-docs/drools-docs-expert/src/main/docbook/en-US/Chapter-Rule_Engine/Section-The_Drools_Rule_Engine.xml , so these changes would also apply to the most recent docs.

Updated content below, the section ids are different but you get the idea

<section id="sect-JBoss_Rules_Reference_Manual-WorkingMemory_and_StatefulStateless_Sessions-Insertion">
<title>Insertion</title>
<para>
<firstterm>Insertion</firstterm> is the act of telling the WorkingMemory about the facts.
</para>

<important>
<para>
In many Expert Systems the term used for this concept is
<firstterm>assert</firstterm> or <firstterm>assertion</firstterm>.
However as the keyword <methodname>assert</methodname> is already used
in many languages, Drools uses the keyword & term <methodname>insert</methodname>.
You will often encounter these terms used interchangably in discussion of
Rules Engines.
</para>
</important>

<para>
When inserted, the rule is examined for matches against the rules. The work
of determining what rules to fire is done during insertion, but no rules are
executed at this time. The rules are executed when
<methodname>fireAllRules()</methodname> is called, and it should only be called
after you have inserted all your facts.
</para>

<para>
It is a common misconception that rule matching occurs when
<methodname>fireAllRules()</methodname> is called.
</para>

<para>
When an Object is inserted it returns a FactHandle. This FactHandle is the
token used to represent your inserted Object inside the WorkingMemory, it is
also how you will interact with the Working Memory when you wish to retract
or modify an object.
</para>

<programlisting language="java">Cheese stilton = new Cheese("stilton");
FactHandle stiltonHandle = session.insert( stilton );</programlisting>

<para>
As mentioned in
<xref linkend="sect-JBoss_Rules_Reference_Manual-The_Drools_Rule_Engine-RuleBase" />
a Working Memory can operate in two assertions modes: <firstterm>equality</firstterm>
and <firstterm>identity</firstterm>. Identity is the default mode. The assertion
mode determines how the Working Memory stores the facts and how it compares the
newly inserted fact to previously inserted ones. If the Working Memory
determines the fact to "be the same" as an already inserted one it will ignore
the new fact and return the FactHandle for the previously inserted one.
</para>

<variablelist>
<varlistentry>
<term>Identity</term>
<listitem>
<para>
Identity Mode uses an <classname>IdentityHashMap</classname>to store all
asserted Objects. New facts being inserted are compared to existing facts
"by reference". A new FactHandle will be returned if the object being
inserted is not a reference to an object that has been inserted previously.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Equality</term>
<listitem>
<para>
Equality Mode uses a <classname>HashMap</classname> to store all asserted
Objects. New facts being inserted are compared to existing facts "by value".
A new FactHandle will be returned if the content of the object is not
identical to that of a previously inserted object.
</para>
</listitem>
</varlistentry>
</variablelist>

</section>