<appendix xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xml:id="appendix.gfdl">
  <title>GNU Free Documentation License</title>
  <sect1 xml:id="sect.gfdl.gnu_free_documentation_license">
    <title>GNU Free Documentation License</title>
    <subtitle>Version 1.3, 3 November 2008</subtitle>
    <para>
      Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
      &lt;<link xlink:href="https://fsf.org/">https://fsf.org/</link>&gt;
    </para>
    <para>
      Everyone is permitted to copy and distribute verbatim copies of this
      license document, but changing it is not allowed.
    </para>
    <orderedlist numeration="arabic" continuation="restarts" startingnumber="0">
      <listitem>
	<para>
	  PREAMBLE
	</para>
	<para>
	  The purpose of this License is to make a manual, textbook, or other
	  functional and useful document "free" in the sense of freedom: to
	  assure everyone the effective freedom to copy and redistribute it,
	  with or without modifying it, either commercially or noncommercially.
	  Secondarily, this License preserves for the author and publisher a
	  way to get credit for their work, while not being considered
	  responsible for modifications made by others.
	</para>
	<para>
	  This License is a kind of "copyleft", which means that derivative
	  works of the document must themselves be free in the same sense. It
	  complements the GNU General Public License, which is a copyleft
	  license designed for free software.
	</para>
	<para>
	  We have designed this License in order to use it for manuals for free
	  software, because free software needs free documentation: a free
	  program should come with manuals providing the same freedoms that
	  the software does. But this License is not limited to software manuals;
	  it can be used for any textual work, regardless of subject matter or
	  whether it is published as a printed book. We recommend this License
	  principally for works whose purpose is instruction or reference.
	</para>
      </listitem>

      <listitem>
	<para>
	  APPLICABILITY AND DEFINITIONS
	</para>
	<para>
	  This License applies to any manual or other work, in any medium, that
	  contains a notice placed by the copyright holder saying it can be
	  distributed under the terms of this License. Such a notice grants a
	  world-wide, royalty-free license, unlimited in duration, to use that
	  work under the conditions stated herein. The "Document", below,
	  refers to any such manual or work. Any member of the public is a
	  licensee, and is addressed as "you". You accept the license if you
	  copy, modify or distribute the work in a way requiring permission
	  under copyright law.
	</para>
	<para>
	  A "Modified Version" of the Document means any work containing the
	  Document or a portion of it, either copied verbatim, or with
	  modifications and/or translated into another language.
	</para>
	<para>
	  A "Secondary Section" is a named appendix or a front-matter section
	  of the Document that deals exclusively with the relationship of the
	  publishers or authors of the Document to the Document's overall
	  subject (or to related matters) and contains nothing that could fall
	  directly within that overall subject. (Thus, if the Document is in
	  part a textbook of mathematics, a Secondary Section may not explain
	  any mathematics.) The relationship could be a matter of historical
	  connection with the subject or with related matters, or of legal,
	  commercial, philosophical, ethical or political position regarding
	  them.
	</para>
	<para>
	  The "Invariant Sections" are certain Secondary Sections whose titles
	  are designated, as being those of Invariant Sections, in the notice
	  that says that the Document is released under this License. If a
	  section does not fit the above definition of Secondary then it is not
	  allowed to be designated as Invariant. The Document may contain zero
	  Invariant Sections. If the Document does not identify any Invariant
	  Sections then there are none.
	</para>
	<para>
	  The "Cover Texts" are certain short passages of text that are listed,
	  as Front-Cover Texts or Back-Cover Texts, in the notice that says
	  that the Document is released under this License. A Front-Cover Text
	  may be at most 5 words, and a Back-Cover Text may be at most 25 words.
	</para>
	<para>
	  A "Transparent" copy of the Document means a machine-readable copy,
	  represented in a format whose specification is available to the
	  general public, that is suitable for revising the document
	  straightforwardly with generic text editors or (for images composed
	  of pixels) generic paint programs or (for drawings) some widely
	  available drawing editor, and that is suitable for input to text
	  formatters or for automatic translation to a variety of formats
	  suitable for input to text formatters. A copy made in an otherwise
	  Transparent file format whose markup, or absence of markup, has been
	  arranged to thwart or discourage subsequent modification by readers
	  is not Transparent. An image format is not Transparent if used for
	  any substantial amount of text. A copy that is not "Transparent" is
	  called "Opaque".
	</para>
	<para>
	  Examples of suitable formats for Transparent copies include plain
	  ASCII without markup, Texinfo input format, LaTeX input format,
	  SGML or XML using a publicly available DTD, and standard-conforming
	  simple HTML, PostScript or PDF designed for human modification.
	  Examples of transparent image formats include PNG, XCF and JPG.
	  Opaque formats include proprietary formats that can be read and
	  edited only by proprietary word processors, SGML or XML for which
	  the DTD and/or processing tools are not generally available, and
	  the machine-generated HTML, PostScript or PDF produced by some word
	  processors for output purposes only.
	</para>
	<para>
	  The "Title Page" means, for a printed book, the title page itself,
	  plus such following pages as are needed to hold, legibly, the
	  material this License requires to appear in the title page. For works
	  in formats which do not have any title page as such, "Title Page"
	  means the text near the most prominent appearance of the work's
	  title, preceding the beginning of the body of the text.
	</para>
	<para>
	  The "publisher" means any person or entity that distributes copies
	  of the Document to the public.
	</para>
	<para>
	  A section "Entitled XYZ" means a named subunit of the Document whose
	  title either is precisely XYZ or contains XYZ in parentheses
	  following text that translates XYZ in another language. (Here XYZ
	  stands for a specific section name mentioned below, such as
	  "Acknowledgements", "Dedications", "Endorsements", or "History".)
	  To "Preserve the Title" of such a section when you modify the
	  Document means that it remains a section "Entitled XYZ" according
	  to this definition.
	</para>
	<para>
	  The Document may include Warranty Disclaimers next to the notice
	  which states that this License applies to the Document. These
	  Warranty Disclaimers are considered to be included by reference in
	  this License, but only as regards disclaiming warranties: any other
	  implication that these Warranty Disclaimers may have is void and has
	  no effect on the meaning of this License.
	</para>
      </listitem>

      <listitem>
	<para>
	  VERBATIM COPYING
	</para>
	<para>
	  You may copy and distribute the Document in any medium, either
	  commercially or noncommercially, provided that this License, the
	  copyright notices, and the license notice saying this License applies
	  to the Document are reproduced in all copies, and that you add no
	  other conditions whatsoever to those of this License. You may not
	  use technical measures to obstruct or control the reading or further
	  copying of the copies you make or distribute. However, you may accept
	  compensation in exchange for copies. If you distribute a large
	  enough number of copies you must also follow the conditions in
	  section 3.
	</para>
	<para>
	  You may also lend copies, under the same conditions stated above,
	  and you may publicly display copies.
	</para>
      </listitem>

      <listitem>
	<para>
	  COPYING IN QUANTITY
	</para>
	<para>
	  If you publish printed copies (or copies in media that commonly have
	  printed covers) of the Document, numbering more than 100, and the
	  Document's license notice requires Cover Texts, you must enclose the
	  copies in covers that carry, clearly and legibly, all these Cover
	  Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on
	  the back cover. Both covers must also clearly and legibly identify
	  you as the publisher of these copies. The front cover must present
	  the full title with all words of the title equally prominent and
	  visible. You may add other material on the covers in addition.
	  Copying with changes limited to the covers, as long as they preserve
	  the title of the Document and satisfy these conditions, can be
	  treated as verbatim copying in other respects.
	</para>
	<para>
	  If the required texts for either cover are too voluminous to fit
	  legibly, you should put the first ones listed (as many as fit
	  reasonably) on the actual cover, and continue the rest onto adjacent
	  pages.
	</para>
	<para>
	  If you publish or distribute Opaque copies of the Document numbering
	  more than 100, you must either include a machine-readable Transparent
	  copy along with each Opaque copy, or state in or with each Opaque
	  copy a computer-network location from which the general network-using
	  public has access to download using public-standard network protocols
	  a complete Transparent copy of the Document, free of added material.
	  If you use the latter option, you must take reasonably prudent steps,
	  when you begin distribution of Opaque copies in quantity, to ensure
	  that this Transparent copy will remain thus accessible at the stated
	  location until at least one year after the last time you distribute
	  an Opaque copy (directly or through your agents or retailers) of that
	  edition to the public.
	</para>
	<para>
	  It is requested, but not required, that you contact the authors of
	  the Document well before redistributing any large number of copies,
	  to give them a chance to provide you with an updated version of the
	  Document.
	</para>
      </listitem>
      
      <listitem>
	<para>
	  MODIFICATIONS
	</para>
	<para>
	  You may copy and distribute a Modified Version of the Document under
	  the conditions of sections 2 and 3 above, provided that you release
	  the Modified Version under precisely this License, with the Modified
	  Version filling the role of the Document, thus licensing
	  distribution and modification of the Modified Version to whoever
	  possesses a copy of it. In addition, you must do these things in the
	  Modified Version:
	</para>
	<orderedlist numeration="upperalpha" inheritnum="ignore">
	  <listitem>
	    <para>
	      Use in the Title Page (and on the covers, if any) a title
	      distinct from that of the Document, and from those of previous
	      versions (which should, if there were any, be listed in the
	      History section of the Document). You may use the same title as
	      a previous version if the original publisher of that version
	      gives permission. 
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      List on the Title Page, as authors, one or more persons or
	      entities responsible for authorship of the modifications in the
	      Modified Version, together with at least five of the principal
	      authors of the Document (all of its principal authors, if it has
	      fewer than five), unless they release you from this requirement. 
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      State on the Title page the name of the publisher of the
	      Modified Version, as the publisher. 
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Preserve all the copyright notices of the Document.
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Add an appropriate copyright notice for your modifications
	      adjacent to the other copyright notices. 
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Include, immediately after the copyright notices, a license
	      notice giving the public permission to use the Modified Version
	      under the terms of this License, in the form shown in the
	      Addendum below.
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Preserve in that license notice the full lists of Invariant
	      Sections and required Cover Texts given in the Document's
	      license notice. 
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Include an unaltered copy of this License.
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Preserve the section Entitled "History", Preserve its Title,
	      and add to it an item stating at least the title, year, new
	      authors, and publisher of the Modified Version as given on the
	      Title Page. If there is no section Entitled "History" in the
	      Document, create one stating the title, year, authors, and
	      publisher of the Document as given on its Title Page, then add
	      an item describing the Modified Version as stated in the previous
	      sentence. 
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Preserve the network location, if any, given in the Document
	      for public access to a Transparent copy of the Document, and
	      likewise the network locations given in the Document for previous
	      versions it was based on. These may be placed in the "History"
	      section. You may omit a network location for a work that was
	      published at least four years before the Document itself, or if
	      the original publisher of the version it refers to gives
	      permission. 
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      For any section Entitled "Acknowledgements" or "Dedications",
	      Preserve the Title of the section, and preserve in the section
	      all the substance and tone of each of the contributor
	      acknowledgements and/or dedications given therein. 
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Preserve all the Invariant Sections of the Document,
	      unaltered in their text and in their titles. Section numbers or
	      the equivalent are not considered part of the section titles. 
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Delete any section Entitled "Endorsements". Such a section
	      may not be included in the Modified Version. 
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Do not retitle any existing section to be Entitled
	      "Endorsements" or to conflict in title with any Invariant
	      Section. 
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Preserve any Warranty Disclaimers.
	    </para>
	  </listitem>
	</orderedlist>
	<para>
	  If the Modified Version includes new front-matter sections or
	  appendices that qualify as Secondary Sections and contain no material
	  copied from the Document, you may at your option designate some or
	  all of these sections as invariant. To do this, add their titles to
	  the list of Invariant Sections in the Modified Version's license
	  notice. These titles must be distinct from any other section titles.
	</para>
	<para>
	  You may add a section Entitled "Endorsements", provided it contains
	  nothing but endorsements of your Modified Version by various
	  parties—for example, statements of peer review or that the text has 
	  been approved by an organization as the authoritative definition of
	  a standard.
	</para>
	<para>
	  You may add a passage of up to five words as a Front-Cover Text, and
	  a passage of up to 25 words as a Back-Cover Text, to the end of the
	  list of Cover Texts in the Modified Version. Only one passage of
	  Front-Cover Text and one of Back-Cover Text may be added by (or
	  through arrangements made by) any one entity. If the Document already
	  includes a cover text for the same cover, previously added by you or
	  by arrangement made by the same entity you are acting on behalf of,
	  you may not add another; but you may replace the old one, on explicit
	  permission from the previous publisher that added the old one.
	</para>
	<para>
	  The author(s) and publisher(s) of the Document do not by this License
	  give permission to use their names for publicity for or to assert or
	  imply endorsement of any Modified Version.
	</para>
      </listitem>

      <listitem>
	<para>
	  COMBINING DOCUMENTS
	</para>
	<para>
	  You may combine the Document with other documents released under this
	  License, under the terms defined in section 4 above for modified
	  versions, provided that you include in the combination all of the
	  Invariant Sections of all of the original documents, unmodified, and
	  list them all as Invariant Sections of your combined work in its
	  license notice, and that you preserve all their Warranty Disclaimers.
	</para>
	<para>
	  The combined work need only contain one copy of this License, and
	  multiple identical Invariant Sections may be replaced with a single
	  copy. If there are multiple Invariant Sections with the same name but
	  different contents, make the title of each such section unique by
	  adding at the end of it, in parentheses, the name of the original
	  author or publisher of that section if known, or else a unique
	  number. Make the same adjustment to the section titles in the list
	  of Invariant Sections in the license notice of the combined work.
	</para>
	<para>
	  In the combination, you must combine any sections Entitled "History"
	  in the various original documents, forming one section Entitled
	  "History"; likewise combine any sections Entitled "Acknowledgements",
	  and any sections Entitled "Dedications". You must delete all sections
	  Entitled "Endorsements".
	</para>
      </listitem>
	
      <listitem>
	<para>
	  COLLECTIONS OF DOCUMENTS
	</para>
	<para>
	  You may make a collection consisting of the Document and other
	  documents released under this License, and replace the individual
	  copies of this License in the various documents with a single copy
	  that is included in the collection, provided that you follow the
	  rules of this License for verbatim copying of each of the documents
	  in all other respects.
	</para>
	<para>
	  You may extract a single document from such a collection, and
	  distribute it individually under this License, provided you insert a
	  copy of this License into the extracted document, and follow this
	  License in all other respects regarding verbatim copying of that
	  document.
	</para>
      </listitem>

      <listitem>
	<para>
	  AGGREGATION WITH EXISTING WORKS
	</para>
	<para>
	  A compilation of the Document or its derivatives with other separate
	  and independent documents or works, in or on a volume of a storage
	  or distribution medium, is called an "aggregate" if the copyright
	  resulting from the compilation is not used to limit the legal rights
	  of the compilation's users beyond what the individual works permit.
	  When the Document is included in an aggregate, this License does not
	  apply to the other works in the aggregate which are not themselves
	  derivative works of the Document.
	</para>
	<para>
	  If the Cover Text requirement of section 3 is applicable to these
	  copies of the Document, then if the Document is less than one half of
	  the entire aggregate, the Document's Cover Texts may be placed on
	  covers that bracket the Document within the aggregate, or the
	  electronic equivalent of covers if the Document is in electronic
	  form. Otherwise they must appear on printed covers that bracket the
	  whole aggregate.
	</para>
      </listitem>

      <listitem>
	<para>
	  TRANSLATION
	</para>
	<para>
	  Translation is considered a kind of modification, so you may
	  distribute translations of the Document under the terms of section 4.
	  Replacing Invariant Sections with translations requires special
	  permission from their copyright holders, but you may include
	  translations of some or all Invariant Sections in addition to the
	  original versions of these Invariant Sections. You may include a
	  translation of this License, and all the license notices in the
	  Document, and any Warranty Disclaimers, provided that you also
	  include the original English version of this License and the original
	  versions of those notices and disclaimers. In case of a disagreement
	  between the translation and the original version of this License or a
	  notice or disclaimer, the original version will prevail.
	</para>
	<para>
	  If a section in the Document is Entitled "Acknowledgements",
	  "Dedications", or "History", the requirement (section 4) to Preserve
	  its Title (section 1) will typically require changing the actual
	  title.
	</para>
      </listitem>

      <listitem>
	<para>
	  TERMINATION
	</para>
	<para>
	  You may not copy, modify, sublicense, or distribute the Document
	  except as expressly provided under this License. Any attempt
	  otherwise to copy, modify, sublicense, or distribute it is void, and
	  will automatically terminate your rights under this License.
	</para>
	<para>
	  However, if you cease all violation of this License, then your
	  license from a particular copyright holder is reinstated (a)
	  provisionally, unless and until the copyright holder explicitly and
	  finally terminates your license, and (b) permanently, if the
	  copyright holder fails to notify you of the violation by some
	  reasonable means prior to 60 days after the cessation.
	</para>
	<para>
	  Moreover, your license from a particular copyright holder is
	  reinstated permanently if the copyright holder notifies you of the
	  violation by some reasonable means, this is the first time you have
	  received notice of violation of this License (for any work) from
	  that copyright holder, and you cure the violation prior to 30 days
	  after your receipt of the notice.
	</para>
	<para>
	  Termination of your rights under this section does not terminate the
	  licenses of parties who have received copies or rights from you
	  under this License. If your rights have been terminated and not
	  permanently reinstated, receipt of a copy of some or all of the same
	  material does not give you any rights to use it.
	</para>
      </listitem>

      <listitem>
	<para>
	  FUTURE VERSIONS OF THIS LICENSE
	</para>
	<para>
	  The Free Software Foundation may publish new, revised versions of
	  the GNU Free Documentation License from time to time. Such new
	  versions will be similar in spirit to the present version, but may
	  differ in detail to address new problems or concerns. See
	  <link xlink:href="https://www.gnu.org/licenses/">
	    https://www.gnu.org/licenses/</link>.
	</para>
	<para>
	  Each version of the License is given a distinguishing version number.
	  If the Document specifies that a particular numbered version of this
	  License "or any later version" applies to it, you have the option of
	  following the terms and conditions either of that specified version
	  or of any later version that has been published (not as a draft) by
	  the Free Software Foundation. If the Document does not specify a
	  version number of this License, you may choose any version ever
	  published (not as a draft) by the Free Software Foundation. If the
	  Document specifies that a proxy can decide which future versions of
	  this License can be used, that proxy's public statement of acceptance
	  of a version permanently authorizes you to choose that version for
	  the Document.
	</para>
      </listitem>

      <listitem>
	<para>
	  RELICENSING
	</para>
	<para>
	  "Massive Multiauthor Collaboration Site" (or "MMC Site") means any
	  World Wide Web server that publishes copyrightable works and also
	  provides prominent facilities for anybody to edit those works. A
	  public wiki that anybody can edit is an example of such a server. A
	  "Massive Multiauthor Collaboration" (or "MMC") contained in the site
	  means any set of copyrightable works thus published on the MMC site.
	</para>
	<para>
	  "CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0
	  license published by Creative Commons Corporation, a not-for-profit
	  corporation with a principal place of business in San Francisco,
	  California, as well as future copyleft versions of that license
	  published by that same organization.
	</para>
	<para>
	  "Incorporate" means to publish or republish a Document, in whole or
	  in part, as part of another Document.
	</para>
	<para>
	  An MMC is "eligible for relicensing" if it is licensed under this
	  License, and if all works that were first published under this
	  License somewhere other than this MMC, and subsequently incorporated
	  in whole or in part into the MMC, (1) had no cover texts or
	  invariant sections, and (2) were thus incorporated prior to November
	  1, 2008.
	</para>
	<para>
	  The operator of an MMC Site may republish an MMC contained in the
	  site under CC-BY-SA on the same site at any time before August 1,
	  2009, provided the MMC is eligible for relicensing.
	</para>
      </listitem>
    </orderedlist>
    <sect2 xml:id="sect.gfdl.how_to_use_this_license_for_your_documents">
      <title>ADDENDUM: How to use this License for your documents</title>
      <para>
	To use this License in a document you have written, include a copy of
	the License in the document and put the following copyright and license
	notices just after the title page:
      </para>
      <literallayout>
    Copyright (C)  YEAR  YOUR NAME.
    Permission is granted to copy, distribute and/or modify this document
    under the terms of the GNU Free Documentation License, Version 1.3
    or any later version published by the Free Software Foundation;
    with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
    A copy of the license is included in the section entitled "GNU
    Free Documentation License".
      </literallayout>
      <para>
	If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
	replace the "with … Texts." line with this:
      </para>
      <literallayout>
    with the Invariant Sections being LIST THEIR TITLES, with the
    Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
      </literallayout>
      <para>
	If you have Invariant Sections without Cover Texts, or some other
	combination of the three, merge those two alternatives to suit the
	situation.
      </para>
      <para>
	If your document contains nontrivial examples of program code, we
	recommend releasing these examples in parallel under your choice of
	free software license, such as the GNU General Public License, to
	permit their use in free software.
      </para>
    </sect2>
  </sect1>
</appendix>
