341 

   342 

   343 

   344                 GNU Free Documentation License

   345                   Version 1.2, November 2002

   346 

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

   348   51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

   349   Everyone is permitted to copy and distribute verbatim copies

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

   351 

   352 0. PREAMBLE

   353 

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

   355 and useful document "free" in the sense of freedom: to assure everyone the

   356 effective freedom to copy and redistribute it, with or without modifying it,

   357 either commercially or noncommercially. Secondarily, this License preserves for

   358 the author and publisher a way to get credit for their work, while not being

   359 considered responsible for modifications made by others.

   360 

   361 This License is a kind of "copyleft", which means that derivative works of the

   362 document must themselves be free in the same sense. It complements the GNU

   363 General Public License, which is a copyleft license designed for free software.

   364 

   365 We have designed this License in order to use it for manuals for free software,

   366 because free software needs free documentation: a free program should come with

   367 manuals providing the same freedoms that the software does. But this License is

   368 not limited to software manuals; it can be used for any textual work,

   369 regardless of subject matter or whether it is published as a printed book. We

   370 recommend this License principally for works whose purpose is instruction or

   371 reference.

   372 

   373 1. APPLICABILITY AND DEFINITIONS

   374 

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

   376 a notice placed by the copyright holder saying it can be distributed under the

   377 terms of this License. Such a notice grants a world-wide, royalty-free license,

   378 unlimited in duration, to use that work under the conditions stated herein. The

   379 "Document", below, refers to any such manual or work. Any member of the public

   380 is a licensee, and is addressed as "you". You accept the license if you copy,

   381 modify or distribute the work in a way requiring permission under copyright

   382 law.

   383 

   384 A "Modified Version" of the Document means any work containing the Document or

   385 a portion of it, either copied verbatim, or with modifications and/or

   386 translated into another language.

   387 

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

   389 Document that deals exclusively with the relationship of the publishers or

   390 authors of the Document to the Document's overall subject (or to related

   391 matters) and contains nothing that could fall directly within that overall

   392 subject. (Thus, if the Document is in part a textbook of mathematics, a

   393 Secondary Section may not explain any mathematics.) The relationship could be a

   394 matter of historical connection with the subject or with related matters, or of

   395 legal, commercial, philosophical, ethical or political position regarding them.

   396 

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

   398 designated, as being those of Invariant Sections, in the notice that says that

   399 the Document is released under this License. If a section does not fit the

   400 above definition of Secondary then it is not allowed to be designated as

   401 Invariant. The Document may contain zero Invariant Sections. If the Document

   402 does not identify any Invariant Sections then there are none.

   403 

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

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

   406 Document is released under this License. A Front-Cover Text may be at most 5

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

   408 

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

   410 in a format whose specification is available to the general public, that is

   411 suitable for revising the document straightforwardly with generic text editors

   412 or (for images composed of pixels) generic paint programs or (for drawings)

   413 some widely available drawing editor, and that is suitable for input to text

   414 formatters or for automatic translation to a variety of formats suitable for

   415 input to text formatters. A copy made in an otherwise Transparent file format

   416 whose markup, or absence of markup, has been arranged to thwart or discourage

   417 subsequent modification by readers is not Transparent. An image format is not

   418 Transparent if used for any substantial amount of text. A copy that is not

   419 "Transparent" is called "Opaque".

   420 

   421 Examples of suitable formats for Transparent copies include plain ASCII without

   422 markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly

   423 available DTD, and standard-conforming simple HTML, PostScript or PDF designed

   424 for human modification. Examples of transparent image formats include PNG, XCF

   425 and JPG. Opaque formats include proprietary formats that can be read and edited

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

   427 processing tools are not generally available, and the machine-generated HTML,

   428 PostScript or PDF produced by some word processors for output purposes only.

   429 

   430 The "Title Page" means, for a printed book, the title page itself, plus such

   431 following pages as are needed to hold, legibly, the material this License

   432 requires to appear in the title page. For works in formats which do not have

   433 any title page as such, "Title Page" means the text near the most prominent

   434 appearance of the work's title, preceding the beginning of the body of the text.

   435 

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

   437 either is precisely XYZ or contains XYZ in parentheses following text that

   438 translates XYZ in another language. (Here XYZ stands for a specific section

   439 name mentioned below, such as "Acknowledgements", "Dedications",

   440 "Endorsements", or "History".) To "Preserve the Title" of such a section when

   441 you modify the Document means that it remains a section "Entitled XYZ"

   442 according to this definition.

   443 

   444 The Document may include Warranty Disclaimers next to the notice which states

   445 that this License applies to the Document. These Warranty Disclaimers are

   446 considered to be included by reference in this License, but only as regards

   447 disclaiming warranties: any other implication that these Warranty Disclaimers

   448 may have is void and has no effect on the meaning of this License.

   449 

   450 2. VERBATIM COPYING

   451 

   452 You may copy and distribute the Document in any medium, either commercially or

   453 noncommercially, provided that this License, the copyright notices, and the

   454 license notice saying this License applies to the Document are reproduced in

   455 all copies, and that you add no other conditions whatsoever to those of this

   456 License. You may not use technical measures to obstruct or control the reading

   457 or further copying of the copies you make or distribute. However, you may

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

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

   460 

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

   462 publicly display copies.

   463 

   464 3. COPYING IN QUANTITY

   465 

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

   467 covers) of the Document, numbering more than 100, and the Document's license

   468 notice requires Cover Texts, you must enclose the copies in covers that carry,

   469 clearly and legibly, all these Cover Texts: Front-Cover Texts on the front

   470 cover, and Back-Cover Texts on the back cover. Both covers must also clearly

   471 and legibly identify you as the publisher of these copies. The front cover must

   472 present the full title with all words of the title equally prominent and

   473 visible. You may add other material on the covers in addition. Copying with

   474 changes limited to the covers, as long as they preserve the title of the

   475 Document and satisfy these conditions, can be treated as verbatim copying in

   476 other respects.

   477 

   478 If the required texts for either cover are too voluminous to fit legibly, you

   479 should put the first ones listed (as many as fit reasonably) on the actual

   480 cover, and continue the rest onto adjacent pages.

   481 

   482 If you publish or distribute Opaque copies of the Document numbering more than

   483 100, you must either include a machine-readable Transparent copy along with each

   484 Opaque copy, or state in or with each Opaque copy a computer-network location

   485 from which the general network-using public has access to download using

   486 public-standard network protocols a complete Transparent copy of the Document,

   487 free of added material. If you use the latter option, you must take reasonably

   488 prudent steps, when you begin distribution of Opaque copies in quantity, to

   489 ensure that this Transparent copy will remain thus accessible at the stated

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

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

   492 public.

   493 

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

   495 well before redistributing any large number of copies, to give them a chance to

   496 provide you with an updated version of the Document.

   497 

   498 4. MODIFICATIONS

   499 

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

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

   502 Version under precisely this License, with the Modified Version filling the role

   503 of the Document, thus licensing distribution and modification of the Modified

   504 Version to whoever possesses a copy of it. In addition, you must do these things

   505 in the Modified Version:

   506 

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

   508        that of the Document, and from those of previous versions (which should,

   509        if there were any, be listed in the History section of the Document).

   510        You may use the same title as a previous version if the original

   511        publisher of that version gives permission.

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

   513        responsible for authorship of the modifications in the Modified Version,

   514        together with at least five of the principal authors of the Document

   515        (all of its principal authors, if it has fewer than five), unless they

   516        release you from this requirement.

   517     C. State on the Title page the name of the publisher of the Modified

   518        Version, as the publisher.

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

   520     E. Add an appropriate copyright notice for your modifications adjacent to

   521        the other copyright notices.

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

   523        giving the public permission to use the Modified Version under the terms

   524        of this License, in the form shown in the Addendum below.

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

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

   527     H. Include an unaltered copy of this License.

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

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

   530        of the Modified Version as given on the Title Page. If there is no

   531        section Entitled "History" in the Document, create one stating the

   532        title, year, authors, and publisher of the Document as given on its

   533        Title Page, then add an item describing the Modified Version as stated

   534        in the previous sentence.

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

   536        access to a Transparent copy of the Document, and likewise the network

   537        locations given in the Document for previous versions it was based on.

   538        These may be placed in the "History" section. You may omit a network

   539        location for a work that was published at least four years before the

   540        Document itself, or if the original publisher of the version it refers

   541        to gives permission.

   542     K. For any section Entitled "Acknowledgements" or "Dedications", Preserve

   543        the Title of the section, and preserve in the section all the substance

   544        and tone of each of the contributor acknowledgements and/or dedications

   545        given therein.

   546     L. Preserve all the Invariant Sections of the Document, unaltered in their

   547        text and in their titles. Section numbers or the equivalent are not

   548        considered part of the section titles.

   549     M. Delete any section Entitled "Endorsements". Such a section may not be

   550        included in the Modified Version.

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

   552        conflict in title with any Invariant Section.

   553     O. Preserve any Warranty Disclaimers.

   554 

   555 If the Modified Version includes new front-matter sections or appendices that

   556 qualify as Secondary Sections and contain no material copied from the Document,

   557 you may at your option designate some or all of these sections as invariant. To

   558 do this, add their titles to the list of Invariant Sections in the Modified

   559 Version's license notice. These titles must be distinct from any other section

   560 titles.

   561 

   562 You may add a section Entitled "Endorsements", provided it contains nothing but

   563 endorsements of your Modified Version by various parties--for example,

   564 statements of peer review or that the text has been approved by an organization

   565 as the authoritative definition of a standard.

   566 

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

   568 of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in

   569 the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover

   570 Text may be added by (or through arrangements made by) any one entity. If the

   571 Document already includes a cover text for the same cover, previously added by

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

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

   574 from the previous publisher that added the old one.

   575 

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

   577 permission to use their names for publicity for or to assert or imply

   578 endorsement of any Modified Version.

   579 

   580 5. COMBINING DOCUMENTS

   581 

   582 You may combine the Document with other documents released under this License,

   583 under the terms defined in section 4 above for modified versions, provided that

   584 you include in the combination all of the Invariant Sections of all of the

   585 original documents, unmodified, and list them all as Invariant Sections of your

   586 combined work in its license notice, and that you preserve all their Warranty

   587 Disclaimers.

   588 

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

   590 identical Invariant Sections may be replaced with a single copy. If there are

   591 multiple Invariant Sections with the same name but different contents, make the

   592 title of each such section unique by adding at the end of it, in parentheses,

   593 the name of the original author or publisher of that section if known, or else

   594 a unique number. Make the same adjustment to the section titles in the list of

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

   596 

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

   598 various original documents, forming one section Entitled "History"; likewise

   599 combine any sections Entitled "Acknowledgements", and any sections Entitled

   600 "Dedications". You must delete all sections Entitled "Endorsements."

   601 

   602 6. COLLECTIONS OF DOCUMENTS

   603 

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

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

   606 in the various documents with a single copy that is included in the collection,

   607 provided that you follow the rules of this License for verbatim copying of each

   608 of the documents in all other respects.

   609 

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

   611 individually under this License, provided you insert a copy of this License into

   612 the extracted document, and follow this License in all other respects regarding

   613 verbatim copying of that document.

   614 

   615 7. AGGREGATION WITH INDEPENDENT WORKS

   616 

   617 A compilation of the Document or its derivatives with other separate and

   618 independent documents or works, in or on a volume of a storage or distribution

   619 medium, is called an "aggregate" if the copyright resulting from the compilation

   620 is not used to limit the legal rights of the compilation's users beyond what the

   621 individual works permit. When the Document is included in an aggregate, this

   622 License does not apply to the other works in the aggregate which are not

   623 themselves derivative works of the Document.

   624 

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

   626 Document, then if the Document is less than one half of the entire aggregate,

   627 the Document's Cover Texts may be placed on covers that bracket the Document

   628 within the aggregate, or the electronic equivalent of covers if the Document is

   629 in electronic form. Otherwise they must appear on printed covers that bracket

   630 the whole aggregate.

   631 

   632 8. TRANSLATION

   633 

   634 Translation is considered a kind of modification, so you may distribute

   635 translations of the Document under the terms of section 4. Replacing Invariant

   636 Sections with translations requires special permission from their copyright

   637 holders, but you may include translations of some or all Invariant Sections in

   638 addition to the original versions of these Invariant Sections. You may include a

   639 translation of this License, and all the license notices in the Document, and

   640 any Warranty Disclaimers, provided that you also include the original English

   641 version of this License and the original versions of those notices and

   642 disclaimers. In case of a disagreement between the translation and the original

   643 version of this License or a notice or disclaimer, the original version will

   644 prevail.

   645 

   646 If a section in the Document is Entitled "Acknowledgements", "Dedications", or

   647 "History", the requirement (section 4) to Preserve its Title (section 1) will

   648 typically require changing the actual title.

   649 

   650 9. TERMINATION

   651 

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

   653 expressly provided for under this License. Any other attempt to copy, modify,

   654 sublicense or distribute the Document is void, and will automatically terminate

   655 your rights under this License. However, parties who have received copies, or

   656 rights, from you under this License will not have their licenses terminated so

   657 long as such parties remain in full compliance.

   658 

   659 10. FUTURE REVISIONS OF THIS LICENSE

   660 

   661 The Free Software Foundation may publish new, revised versions of the GNU Free

   662 Documentation License from time to time. Such new versions will be similar in

   663 spirit to the present version, but may differ in detail to address new problems

   664 or concerns. See http://www.gnu.org/copyleft/.

   665 

   666 Each version of the License is given a distinguishing version number. If the

   667 Document specifies that a particular numbered version of this License "or any

   668 later version" applies to it, you have the option of following the terms and

   669 conditions either of that specified version or of any later version that has

   670 been published (not as a draft) by the Free Software Foundation. If the Document

   671 does not specify a version number of this License, you may choose any version

   672 ever published (not as a draft) by the Free Software Foundation.  How to use

   673 this License for your documents

   674 

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

   676 License in the document and put the following copyright and license notices just

   677 after the title page:

   678 

   679   Copyright (c)  YEAR  YOUR NAME.

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

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

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

   683   with no Invariant Sections, no Front-Cover Texts, and no Back-Cover

   684   Texts.  A copy of the license is included in the section entitled "GNU

   685   Free Documentation License".

   686 

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

   688 the "with...Texts." line with this:

   689 

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

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

   692 

   693 If you have Invariant Sections without Cover Texts, or some other combination of

   694 the three, merge those two alternatives to suit the situation.

   695 

   696 If your document contains nontrivial examples of program code, we recommend

   697 releasing these examples in parallel under your choice of free software license,

   698 such as the GNU General Public License, to permit their use in free software.

   699