# The GNU Free Documentation License.
#+begin_center
Version 1.3, 3 November 2008
#+end_center

# This file is intended to be included within another document.

#+begin_verse
Copyright \copy{} 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
https://fsf.org/

Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
#+end_verse

0. [@0] PREAMBLE

   The purpose of this License is to make a manual, textbook, or other
   functional and useful document @@texinfo:@dfn{@@free@@texinfo:}@@
   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.

   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.

   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.

1. APPLICABILITY AND DEFINITIONS

   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.

   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.

   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.

   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.

   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.

   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".

   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.

   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.

   The "publisher" means any person or entity that distributes copies
   of the Document to the public.

   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.

   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.

2. VERBATIM COPYING

   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.

   You may also lend copies, under the same conditions stated above,
   and you may publicly display copies.

3. COPYING IN QUANTITY

   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.

   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.

   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.

   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.

4. MODIFICATIONS

   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:

   #+attr_texinfo: :enum A
   1. 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.

   2. 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.

   3. State on the Title page the name of the publisher of the
      Modified Version, as the publisher.

   4. Preserve all the copyright notices of the Document.

   5. Add an appropriate copyright notice for your modifications
      adjacent to the other copyright notices.

   6. 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.

   7. Preserve in that license notice the full lists of Invariant
      Sections and required Cover Texts given in the Document's
      license notice.

   8. Include an unaltered copy of this License.

   9. 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.

   10. 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.

   11. 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.

   12. 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.

   13. Delete any section Entitled "Endorsements". Such a section may
       not be included in the Modified Version.

   14. Do not retitle any existing section to be Entitled
       "Endorsements" or to conflict in title with any Invariant
       Section.

   15. Preserve any Warranty Disclaimers.

   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.

   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.

   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.

   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.

5. COMBINING DOCUMENTS

   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.

   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.

   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."

6. COLLECTIONS OF DOCUMENTS

   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.

   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.

7. AGGREGATION WITH INDEPENDENT WORKS

   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.

   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.

8. TRANSLATION

   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.

   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.

9. TERMINATION

   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.

   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.

   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.

   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.

10. FUTURE REVISIONS OF THIS LICENSE

    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
    https://www.gnu.org/copyleft/.

    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.

11. RELICENSING

    "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.

    "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.

    "Incorporate" means to publish or republish a Document, in whole
    or in part, as part of another Document.

    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.

    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.

#+texinfo: @page

* ADDENDUM: How to use this License for your documents
:PROPERTIES:
:UNNUMBERED: notoc
:END:

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:

#+begin_example
    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''.
#+end_example

If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
replace the "with...Texts."\nbsp{}line with this:

#+begin_example
      with the Invariant Sections being LIST THEIR TITLES, with
      the Front-Cover Texts being LIST, and with the Back-Cover Texts
      being LIST.
#+end_example

If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the
situation.

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.

