1@c The GNU Free Documentation License. 2@center Version 1.3, 3 November 2008 3 4@c This file is intended to be included within another document, 5@c hence no sectioning command or @node. 6 7@display 8Copyright @copyright{} 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. 9@uref{http://fsf.org/} 10 11Everyone is permitted to copy and distribute verbatim copies 12of this license document, but changing it is not allowed. 13@end display 14 15@enumerate 0 16@item 17PREAMBLE 18 19The purpose of this License is to make a manual, textbook, or other 20functional and useful document @dfn{free} in the sense of freedom: to 21assure everyone the effective freedom to copy and redistribute it, 22with or without modifying it, either commercially or noncommercially. 23Secondarily, this License preserves for the author and publisher a way 24to get credit for their work, while not being considered responsible 25for modifications made by others. 26 27This License is a kind of ``copyleft'', which means that derivative 28works of the document must themselves be free in the same sense. It 29complements the GNU General Public License, which is a copyleft 30license designed for free software. 31 32We have designed this License in order to use it for manuals for free 33software, because free software needs free documentation: a free 34program should come with manuals providing the same freedoms that the 35software does. But this License is not limited to software manuals; 36it can be used for any textual work, regardless of subject matter or 37whether it is published as a printed book. We recommend this License 38principally for works whose purpose is instruction or reference. 39 40@item 41APPLICABILITY AND DEFINITIONS 42 43This License applies to any manual or other work, in any medium, that 44contains a notice placed by the copyright holder saying it can be 45distributed under the terms of this License. Such a notice grants a 46world-wide, royalty-free license, unlimited in duration, to use that 47work under the conditions stated herein. The ``Document'', below, 48refers to any such manual or work. Any member of the public is a 49licensee, and is addressed as ``you''. You accept the license if you 50copy, modify or distribute the work in a way requiring permission 51under copyright law. 52 53A ``Modified Version'' of the Document means any work containing the 54Document or a portion of it, either copied verbatim, or with 55modifications and/or translated into another language. 56 57A ``Secondary Section'' is a named appendix or a front-matter section 58of the Document that deals exclusively with the relationship of the 59publishers or authors of the Document to the Document's overall 60subject (or to related matters) and contains nothing that could fall 61directly within that overall subject. (Thus, if the Document is in 62part a textbook of mathematics, a Secondary Section may not explain 63any mathematics.) The relationship could be a matter of historical 64connection with the subject or with related matters, or of legal, 65commercial, philosophical, ethical or political position regarding 66them. 67 68The ``Invariant Sections'' are certain Secondary Sections whose titles 69are designated, as being those of Invariant Sections, in the notice 70that says that the Document is released under this License. If a 71section does not fit the above definition of Secondary then it is not 72allowed to be designated as Invariant. The Document may contain zero 73Invariant Sections. If the Document does not identify any Invariant 74Sections then there are none. 75 76The ``Cover Texts'' are certain short passages of text that are listed, 77as Front-Cover Texts or Back-Cover Texts, in the notice that says that 78the Document is released under this License. A Front-Cover Text may 79be at most 5 words, and a Back-Cover Text may be at most 25 words. 80 81A ``Transparent'' copy of the Document means a machine-readable copy, 82represented in a format whose specification is available to the 83general public, that is suitable for revising the document 84straightforwardly with generic text editors or (for images composed of 85pixels) generic paint programs or (for drawings) some widely available 86drawing editor, and that is suitable for input to text formatters or 87for automatic translation to a variety of formats suitable for input 88to text formatters. A copy made in an otherwise Transparent file 89format whose markup, or absence of markup, has been arranged to thwart 90or discourage subsequent modification by readers is not Transparent. 91An image format is not Transparent if used for any substantial amount 92of text. A copy that is not ``Transparent'' is called ``Opaque''. 93 94Examples of suitable formats for Transparent copies include plain 95ASCII without markup, Texinfo input format, La@TeX{} input 96format, SGML or XML using a publicly available 97DTD, and standard-conforming simple HTML, 98PostScript or PDF designed for human modification. Examples 99of transparent image formats include PNG, XCF and 100JPG. Opaque formats include proprietary formats that can be 101read and edited only by proprietary word processors, SGML or 102XML for which the DTD and/or processing tools are 103not generally available, and the machine-generated HTML, 104PostScript or PDF produced by some word processors for 105output purposes only. 106 107The ``Title Page'' means, for a printed book, the title page itself, 108plus such following pages as are needed to hold, legibly, the material 109this License requires to appear in the title page. For works in 110formats which do not have any title page as such, ``Title Page'' means 111the text near the most prominent appearance of the work's title, 112preceding the beginning of the body of the text. 113 114The ``publisher'' means any person or entity that distributes copies 115of the Document to the public. 116 117A section ``Entitled XYZ'' means a named subunit of the Document whose 118title either is precisely XYZ or contains XYZ in parentheses following 119text that translates XYZ in another language. (Here XYZ stands for a 120specific section name mentioned below, such as ``Acknowledgements'', 121``Dedications'', ``Endorsements'', or ``History''.) To ``Preserve the Title'' 122of such a section when you modify the Document means that it remains a 123section ``Entitled XYZ'' according to this definition. 124 125The Document may include Warranty Disclaimers next to the notice which 126states that this License applies to the Document. These Warranty 127Disclaimers are considered to be included by reference in this 128License, but only as regards disclaiming warranties: any other 129implication that these Warranty Disclaimers may have is void and has 130no effect on the meaning of this License. 131 132@item 133VERBATIM COPYING 134 135You may copy and distribute the Document in any medium, either 136commercially or noncommercially, provided that this License, the 137copyright notices, and the license notice saying this License applies 138to the Document are reproduced in all copies, and that you add no other 139conditions whatsoever to those of this License. You may not use 140technical measures to obstruct or control the reading or further 141copying of the copies you make or distribute. However, you may accept 142compensation in exchange for copies. If you distribute a large enough 143number of copies you must also follow the conditions in section 3. 144 145You may also lend copies, under the same conditions stated above, and 146you may publicly display copies. 147 148@item 149COPYING IN QUANTITY 150 151If you publish printed copies (or copies in media that commonly have 152printed covers) of the Document, numbering more than 100, and the 153Document's license notice requires Cover Texts, you must enclose the 154copies in covers that carry, clearly and legibly, all these Cover 155Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on 156the back cover. Both covers must also clearly and legibly identify 157you as the publisher of these copies. The front cover must present 158the full title with all words of the title equally prominent and 159visible. You may add other material on the covers in addition. 160Copying with changes limited to the covers, as long as they preserve 161the title of the Document and satisfy these conditions, can be treated 162as verbatim copying in other respects. 163 164If the required texts for either cover are too voluminous to fit 165legibly, you should put the first ones listed (as many as fit 166reasonably) on the actual cover, and continue the rest onto adjacent 167pages. 168 169If you publish or distribute Opaque copies of the Document numbering 170more than 100, you must either include a machine-readable Transparent 171copy along with each Opaque copy, or state in or with each Opaque copy 172a computer-network location from which the general network-using 173public has access to download using public-standard network protocols 174a complete Transparent copy of the Document, free of added material. 175If you use the latter option, you must take reasonably prudent steps, 176when you begin distribution of Opaque copies in quantity, to ensure 177that this Transparent copy will remain thus accessible at the stated 178location until at least one year after the last time you distribute an 179Opaque copy (directly or through your agents or retailers) of that 180edition to the public. 181 182It is requested, but not required, that you contact the authors of the 183Document well before redistributing any large number of copies, to give 184them a chance to provide you with an updated version of the Document. 185 186@item 187MODIFICATIONS 188 189You may copy and distribute a Modified Version of the Document under 190the conditions of sections 2 and 3 above, provided that you release 191the Modified Version under precisely this License, with the Modified 192Version filling the role of the Document, thus licensing distribution 193and modification of the Modified Version to whoever possesses a copy 194of it. In addition, you must do these things in the Modified Version: 195 196@enumerate A 197@item 198Use in the Title Page (and on the covers, if any) a title distinct 199from that of the Document, and from those of previous versions 200(which should, if there were any, be listed in the History section 201of the Document). You may use the same title as a previous version 202if the original publisher of that version gives permission. 203 204@item 205List on the Title Page, as authors, one or more persons or entities 206responsible for authorship of the modifications in the Modified 207Version, together with at least five of the principal authors of the 208Document (all of its principal authors, if it has fewer than five), 209unless they release you from this requirement. 210 211@item 212State on the Title page the name of the publisher of the 213Modified Version, as the publisher. 214 215@item 216Preserve all the copyright notices of the Document. 217 218@item 219Add an appropriate copyright notice for your modifications 220adjacent to the other copyright notices. 221 222@item 223Include, immediately after the copyright notices, a license notice 224giving the public permission to use the Modified Version under the 225terms of this License, in the form shown in the Addendum below. 226 227@item 228Preserve in that license notice the full lists of Invariant Sections 229and required Cover Texts given in the Document's license notice. 230 231@item 232Include an unaltered copy of this License. 233 234@item 235Preserve the section Entitled ``History'', Preserve its Title, and add 236to it an item stating at least the title, year, new authors, and 237publisher of the Modified Version as given on the Title Page. If 238there is no section Entitled ``History'' in the Document, create one 239stating the title, year, authors, and publisher of the Document as 240given on its Title Page, then add an item describing the Modified 241Version as stated in the previous sentence. 242 243@item 244Preserve the network location, if any, given in the Document for 245public access to a Transparent copy of the Document, and likewise 246the network locations given in the Document for previous versions 247it was based on. These may be placed in the ``History'' section. 248You may omit a network location for a work that was published at 249least four years before the Document itself, or if the original 250publisher of the version it refers to gives permission. 251 252@item 253For any section Entitled ``Acknowledgements'' or ``Dedications'', Preserve 254the Title of the section, and preserve in the section all the 255substance and tone of each of the contributor acknowledgements and/or 256dedications given therein. 257 258@item 259Preserve all the Invariant Sections of the Document, 260unaltered in their text and in their titles. Section numbers 261or the equivalent are not considered part of the section titles. 262 263@item 264Delete any section Entitled ``Endorsements''. Such a section 265may not be included in the Modified Version. 266 267@item 268Do not retitle any existing section to be Entitled ``Endorsements'' or 269to conflict in title with any Invariant Section. 270 271@item 272Preserve any Warranty Disclaimers. 273@end enumerate 274 275If the Modified Version includes new front-matter sections or 276appendices that qualify as Secondary Sections and contain no material 277copied from the Document, you may at your option designate some or all 278of these sections as invariant. To do this, add their titles to the 279list of Invariant Sections in the Modified Version's license notice. 280These titles must be distinct from any other section titles. 281 282You may add a section Entitled ``Endorsements'', provided it contains 283nothing but endorsements of your Modified Version by various 284parties---for example, statements of peer review or that the text has 285been approved by an organization as the authoritative definition of a 286standard. 287 288You may add a passage of up to five words as a Front-Cover Text, and a 289passage of up to 25 words as a Back-Cover Text, to the end of the list 290of Cover Texts in the Modified Version. Only one passage of 291Front-Cover Text and one of Back-Cover Text may be added by (or 292through arrangements made by) any one entity. If the Document already 293includes a cover text for the same cover, previously added by you or 294by arrangement made by the same entity you are acting on behalf of, 295you may not add another; but you may replace the old one, on explicit 296permission from the previous publisher that added the old one. 297 298The author(s) and publisher(s) of the Document do not by this License 299give permission to use their names for publicity for or to assert or 300imply endorsement of any Modified Version. 301 302@item 303COMBINING DOCUMENTS 304 305You may combine the Document with other documents released under this 306License, under the terms defined in section 4 above for modified 307versions, provided that you include in the combination all of the 308Invariant Sections of all of the original documents, unmodified, and 309list them all as Invariant Sections of your combined work in its 310license notice, and that you preserve all their Warranty Disclaimers. 311 312The combined work need only contain one copy of this License, and 313multiple identical Invariant Sections may be replaced with a single 314copy. If there are multiple Invariant Sections with the same name but 315different contents, make the title of each such section unique by 316adding at the end of it, in parentheses, the name of the original 317author or publisher of that section if known, or else a unique number. 318Make the same adjustment to the section titles in the list of 319Invariant Sections in the license notice of the combined work. 320 321In the combination, you must combine any sections Entitled ``History'' 322in the various original documents, forming one section Entitled 323``History''; likewise combine any sections Entitled ``Acknowledgements'', 324and any sections Entitled ``Dedications''. You must delete all 325sections Entitled ``Endorsements.'' 326 327@item 328COLLECTIONS OF DOCUMENTS 329 330You may make a collection consisting of the Document and other documents 331released under this License, and replace the individual copies of this 332License in the various documents with a single copy that is included in 333the collection, provided that you follow the rules of this License for 334verbatim copying of each of the documents in all other respects. 335 336You may extract a single document from such a collection, and distribute 337it individually under this License, provided you insert a copy of this 338License into the extracted document, and follow this License in all 339other respects regarding verbatim copying of that document. 340 341@item 342AGGREGATION WITH INDEPENDENT WORKS 343 344A compilation of the Document or its derivatives with other separate 345and independent documents or works, in or on a volume of a storage or 346distribution medium, is called an ``aggregate'' if the copyright 347resulting from the compilation is not used to limit the legal rights 348of the compilation's users beyond what the individual works permit. 349When the Document is included in an aggregate, this License does not 350apply to the other works in the aggregate which are not themselves 351derivative works of the Document. 352 353If the Cover Text requirement of section 3 is applicable to these 354copies of the Document, then if the Document is less than one half of 355the entire aggregate, the Document's Cover Texts may be placed on 356covers that bracket the Document within the aggregate, or the 357electronic equivalent of covers if the Document is in electronic form. 358Otherwise they must appear on printed covers that bracket the whole 359aggregate. 360 361@item 362TRANSLATION 363 364Translation is considered a kind of modification, so you may 365distribute translations of the Document under the terms of section 4. 366Replacing Invariant Sections with translations requires special 367permission from their copyright holders, but you may include 368translations of some or all Invariant Sections in addition to the 369original versions of these Invariant Sections. You may include a 370translation of this License, and all the license notices in the 371Document, and any Warranty Disclaimers, provided that you also include 372the original English version of this License and the original versions 373of those notices and disclaimers. In case of a disagreement between 374the translation and the original version of this License or a notice 375or disclaimer, the original version will prevail. 376 377If a section in the Document is Entitled ``Acknowledgements'', 378``Dedications'', or ``History'', the requirement (section 4) to Preserve 379its Title (section 1) will typically require changing the actual 380title. 381 382@item 383TERMINATION 384 385You may not copy, modify, sublicense, or distribute the Document 386except as expressly provided under this License. Any attempt 387otherwise to copy, modify, sublicense, or distribute it is void, and 388will automatically terminate your rights under this License. 389 390However, if you cease all violation of this License, then your license 391from a particular copyright holder is reinstated (a) provisionally, 392unless and until the copyright holder explicitly and finally 393terminates your license, and (b) permanently, if the copyright holder 394fails to notify you of the violation by some reasonable means prior to 39560 days after the cessation. 396 397Moreover, your license from a particular copyright holder is 398reinstated permanently if the copyright holder notifies you of the 399violation by some reasonable means, this is the first time you have 400received notice of violation of this License (for any work) from that 401copyright holder, and you cure the violation prior to 30 days after 402your receipt of the notice. 403 404Termination of your rights under this section does not terminate the 405licenses of parties who have received copies or rights from you under 406this License. If your rights have been terminated and not permanently 407reinstated, receipt of a copy of some or all of the same material does 408not give you any rights to use it. 409 410@item 411FUTURE REVISIONS OF THIS LICENSE 412 413The Free Software Foundation may publish new, revised versions 414of the GNU Free Documentation License from time to time. Such new 415versions will be similar in spirit to the present version, but may 416differ in detail to address new problems or concerns. See 417@uref{http://www.gnu.org/copyleft/}. 418 419Each version of the License is given a distinguishing version number. 420If the Document specifies that a particular numbered version of this 421License ``or any later version'' applies to it, you have the option of 422following the terms and conditions either of that specified version or 423of any later version that has been published (not as a draft) by the 424Free Software Foundation. If the Document does not specify a version 425number of this License, you may choose any version ever published (not 426as a draft) by the Free Software Foundation. If the Document 427specifies that a proxy can decide which future versions of this 428License can be used, that proxy's public statement of acceptance of a 429version permanently authorizes you to choose that version for the 430Document. 431 432@item 433RELICENSING 434 435``Massive Multiauthor Collaboration Site'' (or ``MMC Site'') means any 436World Wide Web server that publishes copyrightable works and also 437provides prominent facilities for anybody to edit those works. A 438public wiki that anybody can edit is an example of such a server. A 439``Massive Multiauthor Collaboration'' (or ``MMC'') contained in the 440site means any set of copyrightable works thus published on the MMC 441site. 442 443``CC-BY-SA'' means the Creative Commons Attribution-Share Alike 3.0 444license published by Creative Commons Corporation, a not-for-profit 445corporation with a principal place of business in San Francisco, 446California, as well as future copyleft versions of that license 447published by that same organization. 448 449``Incorporate'' means to publish or republish a Document, in whole or 450in part, as part of another Document. 451 452An MMC is ``eligible for relicensing'' if it is licensed under this 453License, and if all works that were first published under this License 454somewhere other than this MMC, and subsequently incorporated in whole 455or in part into the MMC, (1) had no cover texts or invariant sections, 456and (2) were thus incorporated prior to November 1, 2008. 457 458The operator of an MMC Site may republish an MMC contained in the site 459under CC-BY-SA on the same site at any time before August 1, 2009, 460provided the MMC is eligible for relicensing. 461 462@end enumerate 463 464@page 465@heading ADDENDUM: How to use this License for your documents 466 467To use this License in a document you have written, include a copy of 468the License in the document and put the following copyright and 469license notices just after the title page: 470 471@smallexample 472@group 473 Copyright (C) @var{year} @var{your name}. 474 Permission is granted to copy, distribute and/or modify this document 475 under the terms of the GNU Free Documentation License, Version 1.3 476 or any later version published by the Free Software Foundation; 477 with no Invariant Sections, no Front-Cover Texts, and no Back-Cover 478 Texts. A copy of the license is included in the section entitled ``GNU 479 Free Documentation License''. 480@end group 481@end smallexample 482 483If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, 484replace the ``with@dots{}Texts.''@: line with this: 485 486@smallexample 487@group 488 with the Invariant Sections being @var{list their titles}, with 489 the Front-Cover Texts being @var{list}, and with the Back-Cover Texts 490 being @var{list}. 491@end group 492@end smallexample 493 494If you have Invariant Sections without Cover Texts, or some other 495combination of the three, merge those two alternatives to suit the 496situation. 497 498If your document contains nontrivial examples of program code, we 499recommend releasing these examples in parallel under your choice of 500free software license, such as the GNU General Public License, 501to permit their use in free software. 502 503@c Local Variables: 504@c ispell-local-pdict: "ispell-dict" 505@c End: 506