path: root/common/cvs-en.xml

 <chapter id="ch-cvs">
    <title>CVS</title>
    
    <para>
      CVS, or Concurrent Versions System, provides a framework for multiple
      users to edit the same files.  As you can imagine, if a group of users
      edits the files in a single directory, chaos would reign.  Using CVS,
      however, a group of people can safely work on the same set of files.  CVS
      keeps the master copy of the files, and it records who changed what and
      when in a central repository.  If conflicts arise, CVS lets you know.  CVS
      is usually used so that programmers can share code, but it also works well
      for documentation.
    </para>
    
    <indexterm>
      <primary>cvs</primary>
    </indexterm>

    <sect1 id="s1-cvs-overview">
      <title>How CVS Works</title>

      <indexterm>
	<primary>cvs</primary>
	<secondary>how it works</secondary>
      </indexterm>

      <indexterm>
	<primary>cvs</primary>
	<secondary>overview</secondary>
      </indexterm>

      <para>
	In most cases, each set of files that make up a package or project is
	stored as a <firstterm>module</firstterm> on the CVS server.
      </para>

      <para>
	When working with files from CVS, you <firstterm>checkout</firstterm> a
	copy of the module on your local file system. After modifying one or
	more files, you <firstterm>commit</firstterm> them back to the central
	CVS repository server.
      </para>

      <para>
	When you commit changes, only changes to files the server knows about
	are committed. In other words, if you created a file in your local
	checkout of a module, the new file is not automatically uploaded to the
	server. You must <firstterm>add</firstterm> the file to the repository
	and then commit it. If you remove a file from your local checkout of a
	module, you must specify that you want to remove it from the repository
	on the CVS server and then commit the removal of the file.
      </para>

      <para>
	The specific commands to perform these actions are discussed in <xref
	linkend="s1-cvs-cvscommands"></xref>.
      </para>

      <para>
	If someone has modified the file between the last time you grabbed the
	file from CVS and when you try to commit a change, it tried to merge the
	changes into the master copy of the CVS server. If the content you
	changed is in a different location in the file than the content changed
	by someone else, chances are, the commit action will go through without
	a <firstterm>conflict</firstterm>. If someone modified the same content
	as the content you just changed and tried to commit, you will see a
	message that a file conflict has occurred.  Thus, you need to
	<firstterm>update</firstterm> your files frequently. It is a good
	practice to update them right before you start modifying a file. Refer
	to <xref linkend="s2-cvs-cvscommands-conflicts"></xref> for instructions
	on resolving conflicts.
      </para>

    </sect1>
<!--
    <sect1 id="s1-cvs-setup">
      <title>Setting Up CVS</title>

      <indexterm>
	<primary>cvs</primary>
	<secondary>setting up</secondary>
      </indexterm>

      <para>
	Before using CVS, you need a CVS account. This section provides
	instructions necessary to setup an account. After getting an account,
	you do not need to perform these actions again.
      </para>


      <sect2 id="s2-cvs-generate-keys">
	<title>Generating Keys</title>
	<indexterm>
	  <primary>OpenSSH</primary>
	  <secondary>authorization keys</secondary>
	</indexterm>
	
	<para>
	  The CVS server uses SSH Protocol 2 keys to authenticate users. Thus, you
	  need to generate a pair of keys before applying for a CVS account.
	</para>
	
	<para>
	  Use the following steps to generate a DSA key used by SSH Protocol 2.
	  It is required for an <computeroutput>rhlinux.redhat.com</computeroutput>
	  CVS account.
	</para>
	<orderedlist>
	  <indexterm>
	    <primary>OpenSSH</primary>
	    <secondary><command>ssh-keygen</command></secondary>
	  </indexterm>
	  <indexterm>
	    <primary><command>ssh-keygen</command></primary>
	  </indexterm>
	  <listitem>
	    <para>To generate a DSA key to work with version 2.0 protocol, at a
	      shell prompt, type the command:
	    </para>
<screen>
<command>ssh-keygen -t dsa</command>
</screen>
	    <para>Accept the default file location of
	      <filename>~/.ssh/id_dsa</filename>. Enter a passphrase different
	      than your account password and confirm it by entering it again.
	    </para>
	  </listitem>
	  <listitem>
	    <para>Copy your new key to the correct file by typing the following at a
	      shell prompt (if <filename>~/.ssh/authorized_keys</filename> already
	      exists, the contents of <filename>~/.ssh/id_dsa.pub</filename> will be
	      appended to the end of the <filename>~/.ssh/authorized_keys</filename>
	      file):
	    </para>
<screen>
<command>cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys</command>
</screen>
	  </listitem>
	  <listitem>
	    <para>Change the permissions of your <filename>.ssh</filename> directory
	      and your keys with the commands 
	    </para>
<screen>
<command>chmod 755 ~/.ssh</command>
<command>chmod 644 ~/.ssh/authorized_keys</command>
</screen>
	  </listitem>
	</orderedlist>
	
	<tip>
	  <title>Tip</title> 
	  <para>
	    You can have your system remember your passphrase so that you do not
	    have to type it every time you access the CVS server. If you are
	    running GNOME, skip to <xref linkend="s1-ssh-with-gnome"></xref>. If you are not
	    running the X Window System, skip to <xref linkend="s1-ssh-without-x"></xref>.
	  </para>
	</tip>
      </sect2>

    </sect1>
-->

    <sect1 id="s1-cvs-configure">
      <title>Configuring CVS on Your System</title>

      <indexterm>
	<primary>cvs</primary>
	<secondary>configuring your system for</secondary>
      </indexterm>

      <para>
	You need to have the RPM package <filename>cvs</filename> installed to
	use CVS.
      </para>

      <indexterm>
	<primary>cvs</primary>
	<secondary>CVSROOT</secondary>
      </indexterm>

      <indexterm>
	<primary>cvs</primary>
	<secondary>CVS_RSH</secondary>
      </indexterm>
      
      <indexterm>
	<primary>CVSROOT</primary>
      </indexterm>

      <indexterm>
	<primary>CVS_RSH</primary>
      </indexterm>

      <indexterm>
	<primary>cvs</primary>
	<secondary><filename>.cvsrc</filename></secondary>
      </indexterm>
      <indexterm>
	<primary><filename>.cvsrc</filename></primary>
      </indexterm>

      <para>
	Follow these steps to configure your CVS environment:
      </para>    
      <orderedlist>
	<listitem>
	  <para>In your favorite Linux editor, add the following lines to your
	    <filename>~/.bashrc</filename>:
	  </para>
<screen>
<computeroutput>export CVSROOT=:pserver:anonymous@rhlinux.redhat.com:/usr/local/CVS
</computeroutput> 
</screen>    
	  <note>
	    <title>Note</title>
	    <para>Only anonymous CVS access is available at this time. Anonymous
	      access does not allow write priviledges.</para>
	  </note>
	</listitem>
	<listitem>
	  <para>Use the command <command>source ~/.bashrc</command> to have the
	    changes take effect.
	  </para>
	</listitem>
	<listitem>
	  <para>Create a file named <filename>.cvsrc</filename> in your home
	    directory.  It should contain the following:
<screen>
<computeroutput>cvs -z3
diff -uN
rdiff -uN
update -dP</computeroutput>
</screen>
	  </para>
	</listitem>
	<listitem>
	  <para>Change directories to where you want your files from CVS to be
	    located, and execute the following commands:
	  </para>
<screen>
<command>cvs login
cvs checkout <replaceable>&lt;module-name&gt;</replaceable></command>
</screen>

	  <para>Refer to <xref linkend="s1-cvs-cvscommands"></xref> if you need help
	    using CVS.
	  </para>
	</listitem>
      </orderedlist>

      <para>
	Once you have checked it out, it doesn't matter what your
	<envar>CVSROOT</envar> is set to because it is stored in the file
	<filename>CVS/Root</filename> for each directory in your local
	repository.
      </para>
      
    </sect1>

    <sect1 id="s1-cvs-cvscommands">
      <title>Basic CVS Commands</title>

      <indexterm>
	<primary>cvs</primary>
	<secondary>commands</secondary>
      </indexterm>

      <para>
	After configuring your system to work with CVS, checkout the modules you
	will be working on.
      </para>

      <sect2 id="s2-cvs-cvscommands-co">
	<title>Checking Out Modules</title>

	<indexterm>
	  <primary>cvs</primary>
	  <secondary>checking out modules</secondary>
	</indexterm>

	<para>
	  You only need to checkout a module once. After a local copy of the
	  module is on your system, it is on your system.
	</para>

	<para>
	  To checkout a module, use the following command:
	</para>

<screen>
<command>cvs co <replaceable>&lt;module-name&gt;</replaceable></command>
</screen>

	<para>
	  For example, to checkout the
	  <computeroutput>redhat-logviewer</computeroutput> module, change to
	  your work directory, and execute the following command:
	</para>

<screen>
<command>cvs co redhat-logviewer</command>
</screen>

	<para>
	  A directory called <filename>redhat-logviewer/</filename> is created
	  in the current directory.
	</para>

	<para>
	  If a branch name is not specified when checking out a module, it is
	  referred to as the <firstterm>HEAD</firstterm> of the CVS module.
	</para>

	<sect3 id="s3-cvs-cvscommands-co-branch">
	  <title>Checking Out Branches of Modules</title>

	  <indexterm>
	    <primary>cvs</primary>
	    <secondary>check out modules</secondary>
	    <tertiary>checking out branches</tertiary>
	  </indexterm>

	  <para>
	    Think of a CVS branch as a version of the files for a particular
	    version of a manual or package.
	  </para>

	  <para>
	    To checkout a branch of a module, use the following command:
	  </para>

<screen>
<command>cvs co -d <replaceable>&lt;directory&gt;</replaceable> -r <replaceable>&lt;branchname&gt;</replaceable> <replaceable>&lt;module-name&gt;</replaceable></command>
</screen>

	  <para>
	    A directory named <replaceable>&lt;directory&gt;</replaceable> is created,
	    and the files for the <replaceable>&lt;branchname&gt;</replaceable> branch
	    of the <replaceable>&lt;module-name&gt;</replaceable> module are copied in
	    the directory.
	  </para>

	  <para>
	    For example, to checkout a branch named BRANCH-VERSION-1.2 from the
	    <computeroutput>mymodule</computeroutput> module, use the command:
	  </para>

<screen>
<command>cvs co -d mymodule-1.2 -r BRANCH-VERSION-1.2 mymodule</command>
</screen>

	  <para>
	    The BRANCH-VERSION-1.2 branch of the module is checked out in the
	  <filename>mymodule-1.2</filename> directory on your system.
	  </para>

	  <para>
	    To determine which branches and tags exist for a file, use the command:
	  </para>
<screen>
<command>cvs status -v <replaceable>&lt;filename&gt;</replaceable></command>
</screen>

	  <para>
	    For example, the status of the file <filename>foo.sgml</filename> is
	    as follows:
	  </para>
<screen>
<computeroutput>
===================================================================
File: foo.sgml    Status: Up-to-date
 
   Working revision:    1.47
   Repository revision: 1.47    /usr/local/CVS/docs/custom-guide/rhl-cg-en.sg
ml,v
   Sticky Tag:          (none)
   Sticky Date:         (none)
   Sticky Options:      (none)
 
   Existing Tags:
        BRANCH-VERSION-1.2              (branch: 1.25.2)
</computeroutput>
</screen>

	  <para>
	    Only tags marked as branches in the second column under the
	    <computeroutput>Existing Tags</computeroutput> section can be
	    checked out as a branch.
	  </para>

	</sect3>

      </sect2>

      <sect2 id="s2-cvs-cvscommands-up">
	<title>Updating Files</title>

	<indexterm>
	  <primary>cvs</primary>
	  <secondary>updating files</secondary>
	</indexterm>

	<para>
	  To retrieve the latest versions of the files in a module, change to
	  the directory that contains the files for the module and execute the
	  command:
	</para>
<screen>
<command>cvs up</command>
</screen>

	<para>
	  The latest versions of all the files in the module are downloaded into
	  your local copy. If you notice a file conflict, refer to <xref
	  linkend="s2-cvs-cvscommands-conflicts"></xref>.
	</para>

      </sect2>

      <sect2 id="s2-cvs-cvscommands-commit">
	<title>Committing Files</title>

	<indexterm>
	  <primary>cvs</primary>
	  <secondary>committing files</secondary>
	</indexterm>

	<para>
	  After modifying files in your local version of a module, commit them
	  to save the changes on the CVS server:
	</para>
<screen>
<command>cvs commit -m "some log message" <filename><replaceable>&lt;filename&gt;</replaceable></filename></command>
</screen>

	<para>
	  The log message should be as descriptive as possible so that you and
	  anyone else working on the module understands what changed. Using a
	  log message such as <userinput>updated some files</userinput> does not
	  accurately describe what has changed and will not help you in the
	  future.
	</para>

	<para>
	  <filename><replaceable>&lt;filename&gt;</replaceable></filename> can
	  be one filename, a series of filenames separated by spaces, or a group
	  of filenames specified using wildcards such as
	  <filename>*.png</filename> or <filename>foo-*.sgml</filename>.
	</para>

	<para>
	  If no filename or group of filenames is specified in the commit
	  command, all files that have been changed in the module, added to the
	  module with the <command>cvs add</command> command, and removed with
	  the <command>cvs rm</command> command are committed to the server. All
	  files in the module means that the command is recursive. It is not
	  good practice to issue the commit command without a filename or group
	  of filenames specified because you might not remember exactly what
	  files changed.
	</para>

	<para>
	  If you notice a file conflict, refer to <xref
	    linkend="s2-cvs-cvscommands-conflicts"></xref>.
	</para>

      </sect2>


      <sect2 id="s2-cvs-cvscommands-add">
	<title>Adding Files</title>

	<indexterm>
	  <primary>cvs</primary>
	  <secondary>adding files</secondary>
	</indexterm>

	<para>
	  To add a file to a module, create the file in your local copy, and
	  execute the following command:
	</para>
<screen>
<command>cvs add <filename>&lt;file-to-add&gt;</filename></command>
</screen>

	<para>
	  After adding the file, you must commit the add to copy it to the
	  server:
	</para>

<screen>
<command>cvs commit -m "some log message" <filename>&lt;file-to-add&gt;</filename></command>
</screen>

      </sect2>

      <sect2 id="s2-cvs-cvscommands-rm">
	<title>Removing Files</title>

	<indexterm>
	  <primary>cvs</primary>
	  <secondary>removing files</secondary>
	</indexterm>

	<para>
	  If a file is no longer needed in the module, use the following command
	  to remove it from your local version and commit the removal to the
	  server. Even though the file is removed from current version of the
	  module, an archived copy is still kept on the server and can be
	  retrieved at any time.
	</para>
<screen>
<command>cvs rm -f <filename>&lt;file-to-remove&gt;</filename></command>
</screen>

	<para>
	  After removing the file, you must commit the removal:
	</para>

<screen>
<command>cvs commit -m "some log message" <filename>&lt;file-to-remove&gt;</filename></command>
</screen>

	<para>
	  You can not use wildcards in the commit command to commit removed
	  files. They must be specified with the complete filenames.
	</para>

	<para>
	  If you need to rename a file, it is best to rename the file on the CVS
	  server so that the history of the file is preserved. If you need to
	  rename a file, contact Tammy (or whoever is the technical lead).
	</para>

      </sect2>

      <sect2 id="s2-cvs-cvscommands-status">
	<title>Status of Files</title>

	<indexterm>
	  <primary>cvs</primary>
	  <secondary>status of files</secondary>
	</indexterm>

	<para>
	  Sometimes it is necessary to view the <firstterm>status</firstterm> of
	  a file in a CVS module. To view the status of a file, use the command:
	</para>

<screen>
<command>cvs status <filename>&lt;filename&gt;</filename></command>
</screen>

	<para>
	  The statuses of a file in the repository are as follows:
	</para>
	<variablelist>
	  <varlistentry>
	    <term><computeroutput>Up-to-date</computeroutput></term>
	    <listitem>
	      <para>Your revision of the file is identical to the latest
		revision on the CVS server.</para>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><computeroutput>Locally Modified</computeroutput></term>
	    <listitem>
	      <para>You have update to the latest revision from the server, but
		then you modified the file in your checkout.</para>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><computeroutput>Locally Added</computeroutput></term>
	    <listitem>
	      <para>You added the file with the <command>cvs add</command>
		command but have not yet committed the addition of the
		file.</para>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><computeroutput>Locally  Removed</computeroutput></term>
	    <listitem>
	      <para>You removed the file with the <command>cvs remove</command>
		command but have not yet committed the removal.</para>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><computeroutput>Needs Checkout</computeroutput></term>
	    <listitem>
	      <para>A newer version of the file is on the server and needs to be
		retrieved. Even though the status includes the word checkout, it
		really means that you need to update your files with the
		<command>cvs update</command> command.</para>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><computeroutput>Needs Patch</computeroutput></term>
	    <listitem>
	      <para>The revision in your local checkout needs a patch to be the
		latest revision from the server. Issue the <command>cvs
		  update</command> command to resolve.</para>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><computeroutput>Needs Merge</computeroutput></term>
	    <listitem>
	      <para>A newer revision exists on the server and your local version
		contains modification not yet committed. This status usually
		occurs if you don't have the latest revision of the file and
		edit it anyway.</para>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><computeroutput>File had conflicts on merge</computeroutput></term>
	    <listitem>
	      <para>Similar to <computeroutput>Needs Merge</computeroutput>,
		except when you tried to issue the <command>cvs update</command>
		command, the differences could not be resolved
		automatically. Refer to <xref linkend="s2-cvs-cvscommands-conflicts"></xref>
		for more information on resolving conflicts.</para>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><computeroutput>Unknown</computeroutput></term>
	    <listitem>
	      <para>The CVS server does not know anything about this file. It
		has not been added or removed locally and has never been
		committed to the server. This status usually occurs for files
		you should not commit to CVS such as
		<filename>generated-index.sgml</filename> or for files that you
		want to add to the repository but have not issued the
		<command>cvs add</command> command for yet.</para>
	    </listitem>
	  </varlistentry>
	</variablelist>

      </sect2>

      <sect2 id="s2-cvs-cvscommands-conflicts">
	<title>Resolving Conflicts</title>

	<indexterm>
	  <primary>cvs</primary>
	  <secondary>resolving conflicts</secondary>
	</indexterm>

	<para>
	  If you modify a file and the same content is modified by someone else
	  and committed first, you will probably see a message similar to the
	  following when committing the file or updating your local copy of the
	  module:
	</para>

<screen>
<computeroutput>
RCS file: /usr/local/CVS/docs/module-name/filename.sgml,v
retrieving revision 1.12
retrieving revision 1.13
Merging differences between 1.12 and 1.13 into filename.sgml
rcsmerge: warning: conflicts during merge
cvs server: conflicts found in filename.sgml
C filename.sgml
</computeroutput>
</screen>

	<para>
	  To resolve the conflict, open the file, search for
	  <computeroutput>&lt;&lt;&lt;&lt;&lt;&lt;&lt;</computeroutput> and determine which version
	  of the content should be in the latest revision of the file in
	  CVS. For example:
	</para>
<screen>
<computeroutput>
&lt;para&gt;
Some sentence.
&lt;&lt;&lt;&lt;&lt;&lt;&lt; filename.sgml
A sentence that was changed in the working copy.
=======
A same sentence that was changed differently and committed.
&gt;&gt;&gt;&gt;&gt;&gt;&gt; 1.13
&lt;/para&gt;
</computeroutput>
</screen>

	<para>
	  The content between the
	  <computeroutput>&lt;&lt;&lt;&lt;&lt;&lt;&lt;</computeroutput>, the
	  <computeroutput>=======</computeroutput> is the content in your 
          working copy. The content between the
	  <computeroutput>=======</computeroutput> and the
	  <computeroutput>&gt;&gt;&gt;&gt;&gt;&gt;&gt;</computeroutput> is
	  the content from the latest revision (or the latest revision
          for the branch) on the server.
	</para>

	<para>
	  Resolve the conflict, and commit the file.
	</para>

      </sect2>


      <sect2 id="s2-cvs-cvscommands-summary">
	<title>Summary</title>

	<indexterm>
	  <primary>cvs</primary>
	  <secondary>commands</secondary>
	  <tertiary>summary of</tertiary>
	</indexterm>

	<para>
	  All commands assume you are in the proper directory for the CVS module.
	</para>

	<table frame="all" id="tb-cvs-basic-commands">
	  <title>Basic CVS Commands</title>
	  <tgroup cols="2">
	    <colspec colnum="1" colname="shortcut" colwidth="30"/>
	    <colspec colnum="2" colname="description" colwidth="60"/>
	    <thead>
	      <row>
		<entry>Command</entry>
		<entry>Description</entry>
	      </row>
	    </thead>
	    <tbody>
	      <row>
		<entry><command>cvs checkout
		    <replaceable>&lt;module-name&gt;</replaceable></command> 
		  or <command>cvs co <replaceable>&lt;module-name&gt;</replaceable></command></entry>
		<entry>Creates a directory called
		  <replaceable>&lt;module-name&gt;</replaceable> with the contents of the
		  module in the directory</entry>
	      </row>
	      <row>
		<entry><command>cvs co -d <replaceable>&lt;directory&gt;</replaceable> -r <replaceable>&lt;branchname&gt;</replaceable> <replaceable>&lt;module-name&gt;</replaceable></command></entry>
		<entry>Creates the <replaceable>&lt;directory&gt;</replaceable> directory
		  with the contents of the <replaceable>&lt;branchname&gt;</replaceable>
		  branch of the <replaceable>&lt;module-name&gt;</replaceable> module</entry>
	      </row>
	      <row>
		<entry><command>cvs update</command> or <command>cvs up</command></entry>	
		<entry>Update your files with the latest files from the CVS server</entry>
	      </row>
	      <row>
		<entry><command>cvs add <replaceable>&lt;filename&gt;</replaceable></command></entry>
		<entry>Add a new file "filename" to the CVS server</entry>		
	      </row>
	      <row>
		<entry><command>cvs commit -m "My message"
		    <replaceable>&lt;filename&gt;</replaceable></command></entry>
		<entry>Update file <replaceable>&lt;filename&gt;</replaceable> with the
		  latest copy from your computer</entry>
	      </row>
	      <row>
		<entry><command>cvs log <replaceable>&lt;filename&gt;</replaceable></command></entry>
		<entry>View the commit messages for the file <replaceable>&lt;filename&gt;</replaceable></entry>
	      </row>
	      <row>
		<entry><command>cvs status <replaceable>&lt;filename&gt;</replaceable></command></entry>
		<entry>View status of the file, such as <computeroutput>Locally
		    Modified</computeroutput></entry>
	      </row>
	      <row>
		<entry><command>cvs status -v <replaceable>&lt;filename&gt;</replaceable></command></entry>
		<entry>View existing tags and branches for file</entry>
	      </row>
	      <row>
		<entry><command>cvs diff <replaceable>&lt;filename&gt;</replaceable></command></entry>
		<entry>Show diff of the working copy of the file and the latest
		  version of the file for the branch</entry>
	      </row>
	      <row>
		<entry><command>cvs diff -r1.1 -r1.2 <replaceable>&lt;filename&gt;</replaceable></command></entry>
		<entry>Show diff of version 1.1 and 1.2 for file</entry>
	      </row>
	    </tbody>
	  </tgroup>
	</table>

	<para>
	  For more information, read the CVS manual available on your system at
	  <filename>/usr/share/doc/cvs-<replaceable>&lt;version-number&gt;</replaceable>/cvs.ps</filename>
	  (the CVS version might vary) and visit the CVS webpage available at
	  <ulink url="http://www.cvshome.org/">http://www.cvshome.org/</ulink>.
	</para>

      <tip>
	<title>Tip</title>
	<para>
	  Since CVS is using ssh to connect to the CVS server, it will prompt
	  you for your password before allowing you to performing your CVS
	  request.  If you want to configure your machine so that you do not
	  have to enter a password, refer to the <ulink
	  url="http://redhat.com/docs/manuals/linux/RHL-9-Manual/custom-guide/s1-openssh-client-config.html"><citetitle>&RH; Linux
	  9 Customization Guide</citetitle></ulink> for details about using
	  <command>ssh-agent</command>.
	</para>
      </tip>
  
      </sect2>
	
    </sect1>
    
  </chapter>