26 -----------------------------------------------------------------------

    27 

    28                 GNU Free Documentation License

    29                    Version 1.1, March 2000

    30 

    31  Copyright (C) 2000  Free Software Foundation, Inc.

    32      51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    33  Everyone is permitted to copy and distribute verbatim copies

    34  of this license document, but changing it is not allowed.

    35 

    36 

    37 0. PREAMBLE

    38 

    39 The purpose of this License is to make a manual, textbook, or other

    40 written document "free" in the sense of freedom: to assure everyone

    41 the effective freedom to copy and redistribute it, with or without

    42 modifying it, either commercially or noncommercially.  Secondarily,

    43 this License preserves for the author and publisher a way to get

    44 credit for their work, while not being considered responsible for

    45 modifications made by others.

    46 

    47 This License is a kind of "copyleft", which means that derivative

    48 works of the document must themselves be free in the same sense.  It

    49 complements the GNU General Public License, which is a copyleft

    50 license designed for free software.

    51 

    52 We have designed this License in order to use it for manuals for free

    53 software, because free software needs free documentation: a free

    54 program should come with manuals providing the same freedoms that the

    55 software does.  But this License is not limited to software manuals;

    56 it can be used for any textual work, regardless of subject matter or

    57 whether it is published as a printed book.  We recommend this License

    58 principally for works whose purpose is instruction or reference.

    59 

    60 

    61 1. APPLICABILITY AND DEFINITIONS

    62 

    63 This License applies to any manual or other work that contains a

    64 notice placed by the copyright holder saying it can be distributed

    65 under the terms of this License.  The "Document", below, refers to any

    66 such manual or work.  Any member of the public is a licensee, and is

    67 addressed as "you".

    68 

    69 A "Modified Version" of the Document means any work containing the

    70 Document or a portion of it, either copied verbatim, or with

    71 modifications and/or translated into another language.

    72 

    73 A "Secondary Section" is a named appendix or a front-matter section of

    74 the Document that deals exclusively with the relationship of the

    75 publishers or authors of the Document to the Document's overall subject

    76 (or to related matters) and contains nothing that could fall directly

    77 within that overall subject.  (For example, if the Document is in part a

    78 textbook of mathematics, a Secondary Section may not explain any

    79 mathematics.)  The relationship could be a matter of historical

    80 connection with the subject or with related matters, or of legal,

    81 commercial, philosophical, ethical or political position regarding

    82 them.

    83 

    84 The "Invariant Sections" are certain Secondary Sections whose titles

    85 are designated, as being those of Invariant Sections, in the notice

    86 that says that the Document is released under this License.

    87 

    88 The "Cover Texts" are certain short passages of text that are listed,

    89 as Front-Cover Texts or Back-Cover Texts, in the notice that says that

    90 the Document is released under this License.

    91 

    92 A "Transparent" copy of the Document means a machine-readable copy,

    93 represented in a format whose specification is available to the

    94 general public, whose contents can be viewed and edited directly and

    95 straightforwardly with generic text editors or (for images composed of

    96 pixels) generic paint programs or (for drawings) some widely available

    97 drawing editor, and that is suitable for input to text formatters or

    98 for automatic translation to a variety of formats suitable for input

    99 to text formatters.  A copy made in an otherwise Transparent file

   100 format whose markup has been designed to thwart or discourage

   101 subsequent modification by readers is not Transparent.  A copy that is

   102 not "Transparent" is called "Opaque".

   103 

   104 Examples of suitable formats for Transparent copies include plain

   105 ASCII without markup, Texinfo input format, LaTeX input format, SGML

   106 or XML using a publicly available DTD, and standard-conforming simple

   107 HTML designed for human modification.  Opaque formats include

   108 PostScript, PDF, proprietary formats that can be read and edited only

   109 by proprietary word processors, SGML or XML for which the DTD and/or

   110 processing tools are not generally available, and the

   111 machine-generated HTML produced by some word processors for output

   112 purposes only.

   113 

   114 The "Title Page" means, for a printed book, the title page itself,

   115 plus such following pages as are needed to hold, legibly, the material

   116 this License requires to appear in the title page.  For works in

   117 formats which do not have any title page as such, "Title Page" means

   118 the text near the most prominent appearance of the work's title,

   119 preceding the beginning of the body of the text.

   120 

   121 

   122 2. VERBATIM COPYING

   123 

   124 You may copy and distribute the Document in any medium, either

   125 commercially or noncommercially, provided that this License, the

   126 copyright notices, and the license notice saying this License applies

   127 to the Document are reproduced in all copies, and that you add no other

   128 conditions whatsoever to those of this License.  You may not use

   129 technical measures to obstruct or control the reading or further

   130 copying of the copies you make or distribute.  However, you may accept

   131 compensation in exchange for copies.  If you distribute a large enough

   132 number of copies you must also follow the conditions in section 3.

   133 

   134 You may also lend copies, under the same conditions stated above, and

   135 you may publicly display copies.

   136 

   137 

   138 3. COPYING IN QUANTITY

   139 

   140 If you publish printed copies of the Document numbering more than 100,

   141 and the Document's license notice requires Cover Texts, you must enclose

   142 the copies in covers that carry, clearly and legibly, all these Cover

   143 Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on

   144 the back cover.  Both covers must also clearly and legibly identify

   145 you as the publisher of these copies.  The front cover must present

   146 the full title with all words of the title equally prominent and

   147 visible.  You may add other material on the covers in addition.

   148 Copying with changes limited to the covers, as long as they preserve

   149 the title of the Document and satisfy these conditions, can be treated

   150 as verbatim copying in other respects.

   151 

   152 If the required texts for either cover are too voluminous to fit

   153 legibly, you should put the first ones listed (as many as fit

   154 reasonably) on the actual cover, and continue the rest onto adjacent

   155 pages.

   156 

   157 If you publish or distribute Opaque copies of the Document numbering

   158 more than 100, you must either include a machine-readable Transparent

   159 copy along with each Opaque copy, or state in or with each Opaque copy

   160 a publicly-accessible computer-network location containing a complete

   161 Transparent copy of the Document, free of added material, which the

   162 general network-using public has access to download anonymously at no

   163 charge using public-standard network protocols.  If you use the latter

   164 option, you must take reasonably prudent steps, when you begin

   165 distribution of Opaque copies in quantity, to ensure that this

   166 Transparent copy will remain thus accessible at the stated location

   167 until at least one year after the last time you distribute an Opaque

   168 copy (directly or through your agents or retailers) of that edition to

   169 the public.

   170 

   171 It is requested, but not required, that you contact the authors of the

   172 Document well before redistributing any large number of copies, to give

   173 them a chance to provide you with an updated version of the Document.

   174 

   175 

   176 4. MODIFICATIONS

   177 

   178 You may copy and distribute a Modified Version of the Document under

   179 the conditions of sections 2 and 3 above, provided that you release

   180 the Modified Version under precisely this License, with the Modified

   181 Version filling the role of the Document, thus licensing distribution

   182 and modification of the Modified Version to whoever possesses a copy

   183 of it.  In addition, you must do these things in the Modified Version:

   184 

   185 A. Use in the Title Page (and on the covers, if any) a title distinct

   186    from that of the Document, and from those of previous versions

   187    (which should, if there were any, be listed in the History section

   188    of the Document).  You may use the same title as a previous version

   189    if the original publisher of that version gives permission.

   190 B. List on the Title Page, as authors, one or more persons or entities

   191    responsible for authorship of the modifications in the Modified

   192    Version, together with at least five of the principal authors of the

   193    Document (all of its principal authors, if it has less than five).

   194 C. State on the Title page the name of the publisher of the

   195    Modified Version, as the publisher.

   196 D. Preserve all the copyright notices of the Document.

   197 E. Add an appropriate copyright notice for your modifications

   198    adjacent to the other copyright notices.

   199 F. Include, immediately after the copyright notices, a license notice

   200    giving the public permission to use the Modified Version under the

   201    terms of this License, in the form shown in the Addendum below.

   202 G. Preserve in that license notice the full lists of Invariant Sections

   203    and required Cover Texts given in the Document's license notice.

   204 H. Include an unaltered copy of this License.

   205 I. Preserve the section entitled "History", and its title, and add to

   206    it an item stating at least the title, year, new authors, and

   207    publisher of the Modified Version as given on the Title Page.  If

   208    there is no section entitled "History" in the Document, create one

   209    stating the title, year, authors, and publisher of the Document as

   210    given on its Title Page, then add an item describing the Modified

   211    Version as stated in the previous sentence.

   212 J. Preserve the network location, if any, given in the Document for

   213    public access to a Transparent copy of the Document, and likewise

   214    the network locations given in the Document for previous versions

   215    it was based on.  These may be placed in the "History" section.

   216    You may omit a network location for a work that was published at

   217    least four years before the Document itself, or if the original

   218    publisher of the version it refers to gives permission.

   219 K. In any section entitled "Acknowledgements" or "Dedications",

   220    preserve the section's title, and preserve in the section all the

   221    substance and tone of each of the contributor acknowledgements

   222    and/or dedications given therein.

   223 L. Preserve all the Invariant Sections of the Document,

   224    unaltered in their text and in their titles.  Section numbers

   225    or the equivalent are not considered part of the section titles.

   226 M. Delete any section entitled "Endorsements".  Such a section

   227    may not be included in the Modified Version.

   228 N. Do not retitle any existing section as "Endorsements"

   229    or to conflict in title with any Invariant Section.

   230 

   231 If the Modified Version includes new front-matter sections or

   232 appendices that qualify as Secondary Sections and contain no material

   233 copied from the Document, you may at your option designate some or all

   234 of these sections as invariant.  To do this, add their titles to the

   235 list of Invariant Sections in the Modified Version's license notice.

   236 These titles must be distinct from any other section titles.

   237 

   238 You may add a section entitled "Endorsements", provided it contains

   239 nothing but endorsements of your Modified Version by various

   240 parties--for example, statements of peer review or that the text has

   241 been approved by an organization as the authoritative definition of a

   242 standard.

   243 

   244 You may add a passage of up to five words as a Front-Cover Text, and a

   245 passage of up to 25 words as a Back-Cover Text, to the end of the list

   246 of Cover Texts in the Modified Version.  Only one passage of

   247 Front-Cover Text and one of Back-Cover Text may be added by (or

   248 through arrangements made by) any one entity.  If the Document already

   249 includes a cover text for the same cover, previously added by you or

   250 by arrangement made by the same entity you are acting on behalf of,

   251 you may not add another; but you may replace the old one, on explicit

   252 permission from the previous publisher that added the old one.

   253 

   254 The author(s) and publisher(s) of the Document do not by this License

   255 give permission to use their names for publicity for or to assert or

   256 imply endorsement of any Modified Version.

   257 

   258 

   259 5. COMBINING DOCUMENTS

   260 

   261 You may combine the Document with other documents released under this

   262 License, under the terms defined in section 4 above for modified

   263 versions, provided that you include in the combination all of the

   264 Invariant Sections of all of the original documents, unmodified, and

   265 list them all as Invariant Sections of your combined work in its

   266 license notice.

   267 

   268 The combined work need only contain one copy of this License, and

   269 multiple identical Invariant Sections may be replaced with a single

   270 copy.  If there are multiple Invariant Sections with the same name but

   271 different contents, make the title of each such section unique by

   272 adding at the end of it, in parentheses, the name of the original

   273 author or publisher of that section if known, or else a unique number.

   274 Make the same adjustment to the section titles in the list of

   275 Invariant Sections in the license notice of the combined work.

   276 

   277 In the combination, you must combine any sections entitled "History"

   278 in the various original documents, forming one section entitled

   279 "History"; likewise combine any sections entitled "Acknowledgements",

   280 and any sections entitled "Dedications".  You must delete all sections

   281 entitled "Endorsements."

   282 

   283 

   284 6. COLLECTIONS OF DOCUMENTS

   285 

   286 You may make a collection consisting of the Document and other documents

   287 released under this License, and replace the individual copies of this

   288 License in the various documents with a single copy that is included in

   289 the collection, provided that you follow the rules of this License for

   290 verbatim copying of each of the documents in all other respects.

   291 

   292 You may extract a single document from such a collection, and distribute

   293 it individually under this License, provided you insert a copy of this

   294 License into the extracted document, and follow this License in all

   295 other respects regarding verbatim copying of that document.

   296 

   297 

   298 7. AGGREGATION WITH INDEPENDENT WORKS

   299 

   300 A compilation of the Document or its derivatives with other separate

   301 and independent documents or works, in or on a volume of a storage or

   302 distribution medium, does not as a whole count as a Modified Version

   303 of the Document, provided no compilation copyright is claimed for the

   304 compilation.  Such a compilation is called an "aggregate", and this

   305 License does not apply to the other self-contained works thus compiled

   306 with the Document, on account of their being thus compiled, if they

   307 are not themselves derivative works of the Document.

   308 

   309 If the Cover Text requirement of section 3 is applicable to these

   310 copies of the Document, then if the Document is less than one quarter

   311 of the entire aggregate, the Document's Cover Texts may be placed on

   312 covers that surround only the Document within the aggregate.

   313 Otherwise they must appear on covers around the whole aggregate.

   314 

   315 

   316 8. TRANSLATION

   317 

   318 Translation is considered a kind of modification, so you may

   319 distribute translations of the Document under the terms of section 4.

   320 Replacing Invariant Sections with translations requires special

   321 permission from their copyright holders, but you may include

   322 translations of some or all Invariant Sections in addition to the

   323 original versions of these Invariant Sections.  You may include a

   324 translation of this License provided that you also include the

   325 original English version of this License.  In case of a disagreement

   326 between the translation and the original English version of this

   327 License, the original English version will prevail.

   328 

   329 

   330 9. TERMINATION

   331 

   332 You may not copy, modify, sublicense, or distribute the Document except

   333 as expressly provided for under this License.  Any other attempt to

   334 copy, modify, sublicense or distribute the Document is void, and will

   335 automatically terminate your rights under this License.  However,

   336 parties who have received copies, or rights, from you under this

   337 License will not have their licenses terminated so long as such

   338 parties remain in full compliance.

   339 

   340 

   341 10. FUTURE REVISIONS OF THIS LICENSE

   342 

   343 The Free Software Foundation may publish new, revised versions

   344 of the GNU Free Documentation License from time to time.  Such new

   345 versions will be similar in spirit to the present version, but may

   346 differ in detail to address new problems or concerns.  See

   347 http://www.gnu.org/copyleft/.

   348 

   349 Each version of the License is given a distinguishing version number.

   350 If the Document specifies that a particular numbered version of this

   351 License "or any later version" applies to it, you have the option of

   352 following the terms and conditions either of that specified version or

   353 of any later version that has been published (not as a draft) by the

   354 Free Software Foundation.  If the Document does not specify a version

   355 number of this License, you may choose any version ever published (not

   356 as a draft) by the Free Software Foundation.

   357 

   358 

   359 ADDENDUM: How to use this License for your documents

   360 

   361 To use this License in a document you have written, include a copy of

   362 the License in the document and put the following copyright and

   363 license notices just after the title page:

   364 

   365       Copyright (c)  YEAR  YOUR NAME.

   366       Permission is granted to copy, distribute and/or modify this document

   367       under the terms of the GNU Free Documentation License, Version 1.1

   368       or any later version published by the Free Software Foundation;

   369       with the Invariant Sections being LIST THEIR TITLES, with the

   370       Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.

   371       A copy of the license is included in the section entitled "GNU

   372       Free Documentation License".

   373 

   374 If you have no Invariant Sections, write "with no Invariant Sections"

   375 instead of saying which ones are invariant.  If you have no

   376 Front-Cover Texts, write "no Front-Cover Texts" instead of

   377 "Front-Cover Texts being LIST"; likewise for Back-Cover Texts.

   378 

   379 If your document contains nontrivial examples of program code, we

   380 recommend releasing these examples in parallel under your choice of

   381 free software license, such as the GNU General Public License,

   382 to permit their use in free software.