1 

     2                 GNU Free Documentation License

     3                   Version 1.2, November 2002

     4 

     5 

     6  Copyright (C) 2000,2001,2002  Free Software Foundation, Inc.

     7      51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

     8  Everyone is permitted to copy and distribute verbatim copies

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

    10 

    11 

    12 0. PREAMBLE

    13 

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

    15 functional and useful document "free" in the sense of freedom: to

    16 assure everyone the effective freedom to copy and redistribute it,

    17 with or without modifying it, either commercially or noncommercially.

    18 Secondarily, this License preserves for the author and publisher a way

    19 to get credit for their work, while not being considered responsible

    20 for modifications made by others.

    21 

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

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

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

    25 license designed for free software.

    26 

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

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

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

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

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

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

    33 principally for works whose purpose is instruction or reference.

    34 

    35 

    36 1. APPLICABILITY AND DEFINITIONS

    37 

    38 This License applies to any manual or other work, in any medium, that

    39 contains a notice placed by the copyright holder saying it can be

    40 distributed under the terms of this License.  Such a notice grants a

    41 world-wide, royalty-free license, unlimited in duration, to use that

    42 work under the conditions stated herein.  The "Document", below,

    43 refers to any such manual or work.  Any member of the public is a

    44 licensee, and is addressed as "you".  You accept the license if you

    45 copy, modify or distribute the work in a way requiring permission

    46 under copyright law.

    47 

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

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

    50 modifications and/or translated into another language.

    51 

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

    53 the Document that deals exclusively with the relationship of the

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

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

    56 within that overall subject.  (Thus, if the Document is in part a

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

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

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

    60 commercial, philosophical, ethical or political position regarding

    61 them.

    62 

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

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

    65 that says that the Document is released under this License.  If a

    66 section does not fit the above definition of Secondary then it is not

    67 allowed to be designated as Invariant.  The Document may contain zero

    68 Invariant Sections.  If the Document does not identify any Invariant

    69 Sections then there are none.

    70 

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

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

    73 the Document is released under this License.  A Front-Cover Text may

    74 be at most 5 words, and a Back-Cover Text may be at most 25 words.

    75 

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

    77 represented in a format whose specification is available to the

    78 general public, that is suitable for revising the document

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

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

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

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

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

    84 format whose markup, or absence of markup, has been arranged to thwart

    85 or discourage subsequent modification by readers is not Transparent.

    86 An image format is not Transparent if used for any substantial amount

    87 of text.  A copy that is not "Transparent" is called "Opaque".

    88 

    89 Examples of suitable formats for Transparent copies include plain

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

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

    92 HTML, PostScript or PDF designed for human modification.  Examples of

    93 transparent image formats include PNG, XCF and JPG.  Opaque formats

    94 include proprietary formats that can be read and edited only by

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

    96 processing tools are not generally available, and the

    97 machine-generated HTML, PostScript or PDF produced by some word

    98 processors for output purposes only.

    99 

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

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

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

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

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

   105 preceding the beginning of the body of the text.

   106 

   107 A section "Entitled XYZ" means a named subunit of the Document whose

   108 title either is precisely XYZ or contains XYZ in parentheses following

   109 text that translates XYZ in another language.  (Here XYZ stands for a

   110 specific section name mentioned below, such as "Acknowledgements",

   111 "Dedications", "Endorsements", or "History".)  To "Preserve the Title"

   112 of such a section when you modify the Document means that it remains a

   113 section "Entitled XYZ" according to this definition.

   114 

   115 The Document may include Warranty Disclaimers next to the notice which

   116 states that this License applies to the Document.  These Warranty

   117 Disclaimers are considered to be included by reference in this

   118 License, but only as regards disclaiming warranties: any other

   119 implication that these Warranty Disclaimers may have is void and has

   120 no effect on the meaning of this License.

   121 

   122 

   123 2. VERBATIM COPYING

   124 

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

   126 commercially or noncommercially, provided that this License, the

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

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

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

   130 technical measures to obstruct or control the reading or further

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

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

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

   134 

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

   136 you may publicly display copies.

   137 

   138 

   139 3. COPYING IN QUANTITY

   140 

   141 If you publish printed copies (or copies in media that commonly have

   142 printed covers) of the Document, numbering more than 100, and the

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

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

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

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

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

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

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

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

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

   152 as verbatim copying in other respects.

   153 

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

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

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

   157 pages.

   158 

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

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

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

   162 a computer-network location from which the general network-using

   163 public has access to download using public-standard network protocols

   164 a complete Transparent copy of the Document, free of added material.

   165 If you use the latter option, you must take reasonably prudent steps,

   166 when you begin distribution of Opaque copies in quantity, to ensure

   167 that this Transparent copy will remain thus accessible at the stated

   168 location until at least one year after the last time you distribute an

   169 Opaque copy (directly or through your agents or retailers) of that

   170 edition to the public.

   171 

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

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

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

   175 

   176 

   177 4. MODIFICATIONS

   178 

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

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

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

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

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

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

   185 

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

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

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

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

   190    if the original publisher of that version gives permission.

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

   192    responsible for authorship of the modifications in the Modified

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

   194    Document (all of its principal authors, if it has fewer than five),

   195    unless they release you from this requirement.

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

   197    Modified Version, as the publisher.

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

   199 E. Add an appropriate copyright notice for your modifications

   200    adjacent to the other copyright notices.

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

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

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

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

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

   206 H. Include an unaltered copy of this License.

   207 I. Preserve the section Entitled "History", Preserve its Title, and add

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

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

   210    there is no section Entitled "History" in the Document, create one

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

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

   213    Version as stated in the previous sentence.

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

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

   216    the network locations given in the Document for previous versions

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

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

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

   220    publisher of the version it refers to gives permission.

   221 K. For any section Entitled "Acknowledgements" or "Dedications",

   222    Preserve the Title of the section, and preserve in the section all

   223    the substance and tone of each of the contributor acknowledgements

   224    and/or dedications given therein.

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

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

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

   228 M. Delete any section Entitled "Endorsements".  Such a section

   229    may not be included in the Modified Version.

   230 N. Do not retitle any existing section to be Entitled "Endorsements"

   231    or to conflict in title with any Invariant Section.

   232 O. Preserve any Warranty Disclaimers.

   233 

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

   235 appendices that qualify as Secondary Sections and contain no material

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

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

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

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

   240 

   241 You may add a section Entitled "Endorsements", provided it contains

   242 nothing but endorsements of your Modified Version by various

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

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

   245 standard.

   246 

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

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

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

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

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

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

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

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

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

   256 

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

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

   259 imply endorsement of any Modified Version.

   260 

   261 

   262 5. COMBINING DOCUMENTS

   263 

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

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

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

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

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

   269 license notice, and that you preserve all their Warranty Disclaimers.

   270 

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

   272 multiple identical Invariant Sections may be replaced with a single

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

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

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

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

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

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

   279 

   280 In the combination, you must combine any sections Entitled "History"

   281 in the various original documents, forming one section Entitled

   282 "History"; likewise combine any sections Entitled "Acknowledgements",

   283 and any sections Entitled "Dedications".  You must delete all sections

   284 Entitled "Endorsements".

   285 

   286 

   287 6. COLLECTIONS OF DOCUMENTS

   288 

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

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

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

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

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

   294 

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

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

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

   298 other respects regarding verbatim copying of that document.

   299 

   300 

   301 7. AGGREGATION WITH INDEPENDENT WORKS

   302 

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

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

   305 distribution medium, is called an "aggregate" if the copyright

   306 resulting from the compilation is not used to limit the legal rights

   307 of the compilation's users beyond what the individual works permit.

   308 When the Document is included in an aggregate, this License does not

   309 apply to the other works in the aggregate which are not themselves

   310 derivative works of the Document.

   311 

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

   313 copies of the Document, then if the Document is less than one half of

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

   315 covers that bracket the Document within the aggregate, or the

   316 electronic equivalent of covers if the Document is in electronic form.

   317 Otherwise they must appear on printed covers that bracket the whole

   318 aggregate.

   319 

   320 

   321 8. TRANSLATION

   322 

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

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

   325 Replacing Invariant Sections with translations requires special

   326 permission from their copyright holders, but you may include

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

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

   329 translation of this License, and all the license notices in the

   330 Document, and any Warranty Disclaimers, provided that you also include

   331 the original English version of this License and the original versions

   332 of those notices and disclaimers.  In case of a disagreement between

   333 the translation and the original version of this License or a notice

   334 or disclaimer, the original version will prevail.

   335 

   336 If a section in the Document is Entitled "Acknowledgements",

   337 "Dedications", or "History", the requirement (section 4) to Preserve

   338 its Title (section 1) will typically require changing the actual

   339 title.

   340 

   341 

   342 9. TERMINATION

   343 

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

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

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

   347 automatically terminate your rights under this License.  However,

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

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

   350 parties remain in full compliance.

   351 

   352 

   353 10. FUTURE REVISIONS OF THIS LICENSE

   354 

   355 The Free Software Foundation may publish new, revised versions

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

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

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

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

   360 

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

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

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

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

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

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

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

   368 as a draft) by the Free Software Foundation.

   369 

   370 

   371 ADDENDUM: How to use this License for your documents

   372 

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

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

   375 license notices just after the title page:

   376 

   377     Copyright (c)  YEAR  YOUR NAME.

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

   379     under the terms of the GNU Free Documentation License, Version 1.2

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

   381     with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.

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

   383     Free Documentation License".

   384 

   385 If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,

   386 replace the "with...Texts." line with this:

   387 

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

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

   390 

   391 If you have Invariant Sections without Cover Texts, or some other

   392 combination of the three, merge those two alternatives to suit the

   393 situation.

   394 

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

   396 recommend releasing these examples in parallel under your choice of

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

   398 to permit their use in free software.