% \section{\centering GNU Free Documentation License}
% \begin{center}
% 
% Version 1.3, 3 November 2008
% 
% Copyright \copyright{} 2000, 2001, 2002, 2007, 2008  Free Software Foundation, Inc.
% 
% \bigskip
% 
% \url{https://fsf.org/}
% 
% \bigskip
% 
% Everyone is permitted to copy and distribute verbatim copies
% of this license document, but changing it is not allowed.
% \end{center}
% 
% \begin{center}
%   {\bf\large Preamble}
% \end{center}
% 
% 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.
% 
% 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.
% 
% \begin{center}
%   {\Large\bf 1. APPLICABILITY AND DEFINITIONS\par}
% \end{center}
% 
% 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 ``\textbf{Document}'', below,
% refers to any such manual or work.  Any member of the public is a
% licensee, and is addressed as ``\textbf{you}''.  You accept the license if you
% copy, modify or distribute the work in a way requiring permission
% under copyright law.
% 
% A ``\textbf{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 ``\textbf{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 ``\textbf{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 ``\textbf{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 ``\textbf{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 ``\textbf{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 ``\textbf{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 ``\textbf{publisher}'' means any person or entity that distributes
% copies of the Document to the public.
% 
% A section ``\textbf{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 ``\textbf{Acknowledgements}'',
% ``\textbf{Dedications}'', ``\textbf{Endorsements}'', or ``\textbf{History}''.)  
% To ``\textbf{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.
% 
% \begin{center}
%   {\Large\bf 2. VERBATIM COPYING\par}
% \end{center}
% 
% 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.
% 
% \begin{center}
%   {\Large\bf 3. COPYING IN QUANTITY\par}
% \end{center}
% 
% 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.
% 
% 
% \begin{center}
%   {\Large\bf 4. MODIFICATIONS\par}
% \end{center}
% 
% 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:
% 
% \begin{itemize}
% \item[A.] 
%   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.
%   
% \item[B.]
%   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.
%   
% \item[C.]
%   State on the Title page the name of the publisher of the
%   Modified Version, as the publisher.
%   
% \item[D.]
%   Preserve all the copyright notices of the Document.
%   
% \item[E.]
%   Add an appropriate copyright notice for your modifications
%   adjacent to the other copyright notices.
%   
% \item[F.]
%   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.
%   
% \item[G.]
%   Preserve in that license notice the full lists of Invariant Sections
%   and required Cover Texts given in the Document's license notice.
%   
% \item[H.]
%   Include an unaltered copy of this License.
%   
% \item[I.]
%   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.
%   
% \item[J.]
%   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.
%   
% \item[K.]
%   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.
%   
% \item[L.]
%   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.
%   
% \item[M.]
%   Delete any section Entitled ``Endorsements''.  Such a section
%   may not be included in the Modified Version.
%   
% \item[N.]
%   Do not retitle any existing section to be Entitled ``Endorsements''
%   or to conflict in title with any Invariant Section.
%   
% \item[O.]
%   Preserve any Warranty Disclaimers.
% \end{itemize}
% 
% 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.
% 
% \begin{center}
%   {\Large\bf 5. COMBINING DOCUMENTS\par}
% \end{center}
% 
% 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''.
% 
% \begin{center}
%   {\Large\bf 6. COLLECTIONS OF DOCUMENTS\par}
% \end{center}
% 
% 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.
% 
% \begin{center}
%   {\Large\bf 7. AGGREGATION WITH INDEPENDENT WORKS\par}
% \end{center}
% 
% 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.
% 
% \begin{center}
%   {\Large\bf 8. TRANSLATION\par}
% \end{center}
% 
% 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.
% 
% \begin{center}
%   {\Large\bf 9. TERMINATION\par}
% \end{center}
% 
% 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.
% 
% \begin{center}
%   {\Large\bf 10. FUTURE REVISIONS OF THIS LICENSE\par}
% \end{center}
% 
% 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
% \texttt{https://www.gnu.org/licenses/}.
% 
% 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.
% 
% \begin{center}
%   {\Large\bf 11. RELICENSING\par}
% \end{center}
% 
% ``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.
% 
% \begin{center}
%   {\Large\bf ADDENDUM: How to use this License for your documents\par}
% \end{center}
% 
% 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:
% 
% \bigskip
% \begin{quote}
%   Copyright \copyright{}  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{quote}
% \bigskip
% 
% If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
% replace the ``with \dots\ Texts.''\ line with this:
% 
% \bigskip
% \begin{quote}
%   with the Invariant Sections being LIST THEIR TITLES, with the
%   Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
% \end{quote}
% \bigskip
% 
% 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.