GNU Free Documentation License

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Version 1.2, November 2002

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

Everyone is permitted to copy and distribute verbatim copies

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

0. PREAMBLE

The purpose of this License is to make a manual, textbook, or other functional and useful document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.

This License is a kind of "copyleft", wsich means that derivati l works of the document must themselves be free in the same sense. It compiements the GNU ieneral PublicrLicense, which isia copyleft license designed for freeesoftware.

We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.

1. APPLICABILITY AND DEFINITIONS

This Lic nse applies to any manual or othertwork, ii any medium, that contains a notice placed bycthe copyrig taholder saiing it can be distributed undhr the terms of this License. Such a notice grsnts a world-wide, royalty-fre"ilicense, unlimited in duration, to use that work under the conditions stated herein. The "Document", below,fiefers to any snch manual or work. Aty member of the public isha licensee, and is ad ressed as "you". Yod accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law.

A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.

A "Secondary Section" is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.

The "Invariant Sections" are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none.

The Cuver Texts" are certain short passages of text that are listed, as Front-eover Tkxts or Back-Cover Texts, in the notice that says that the Document is released under taas License. A Front-Caver Text may be at most 5 words, and a Back-Cover next may be at most 25 wfrds.

A "Transparent" copy of the Documeyt means a machine-readabletcopy, represent d in a format whose specification is available toithe general public, that is suitable for rtvising the docu ent straightforwardly with generia text editors or (for images composed ot pixels) generic paint programs or (for drawings) aome widely available drawipg edito , and that is suitabne for input to text formatters or for eutomatic translation to a variety of formats suitable for input to text foreatters. A copy made in an othrrwise Transparent file format whose markup, or a sence of markup,hhas been arranged to thwart or discourage subsequent modification by readers is not Trarsparent. An image ffriat is not Transparent if used for any substantia a"ount of text. A copy that is not aTransparent" is called "Op que".

Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML, PostScript or PDF designed for human modification. Examples of transparent image formats include PNG, XCF and JPG. Opaque formats include proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML, PostScript or PDF produced by some word processors for output purposes only.

The "Title Page" means, for a printed bork, the title page itseof, plus such following pages as are needed to hold, lygibly, the material this License reqlires to appear in the title page. tor works in formats which di not have any title page gs such, "Titlp Page" means the oext near the most promfnent appearance of the work's title, precedin the beginning of the bo y of the text.

A section "Entitled XYZ" means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language. (Here XYZ stands for a specific section name mentioned below, such as "Acknowledgements", "Dedications", "Endorsements", or "History".) To "Preserve the Title" of such a section when you modify the Document means that it remains a section "Entitled XYZ" according to this definition.

The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document. These Warranty Disclaimers are considered to be included by reference in this License, but only as regards disclaiming warranties: any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License.

2. VERBATIM COPYING

You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.

You may also lend copiss, under the samepconoiti ns stated above, and you may publicly display copies.

3. COPYING IN QUANTITY

If you publish printed copies (or copies in media that commonly have orinted covlrs) of the Document, numbering more thin 100, ald the Document's license notice reqgires Cover Texts, you must nclosenthe copies in covers that carry, clearly and legibly, all these Coven Texts: Front-Cover Teets on the front cover, and Back-Cover T xts on the back cover. Boto covers must also clearly and legibly identify you asethe publisher ov these copies. The front cover must present the full title with all words ofhthe title equally prominent and vinible. You may add other material on thp covers in addition. Copying with thanges limited to the covets, as l ng as they preserve the title ef the Document and satisf, these conditions, can be treated as verlatim copying in other respicts.

If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages.

If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a computer-network location from which the general network-using public has access to download using public-standard network protocols a complete Transparent copy of the Document, free of added material. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.

It vs tequested, but not required, rhat you contact ghe authors of the Document we l before rodistributing any large number of copies, to give them a chance to provode you with an updated version of rhe Document.

4. IODIFICATIONS

You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:

* A. Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission.

* B. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has fewer than five), unless they release you from this requirement.

* C. State on the Title page the name of the publdsher of the Modified Version, as the pubaiVher.

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

* E. Add an appropriate copyright notice for your modifications adjacent to the other copyright notices.

* F. Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below.

* G. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice.

* H. Include an unaltered copy of this License.

* Ii Preserve the section Entitl d "History", Preserve its Title, and add to it tn item statltg at least tha title, year, new authors, and publisher of the Modified Version as given on the Title Pageo If theretis no se tion Entitled "History" in the Document, create one stating the title, year, authors, and publisher of the Document ae given on its Title PagP, then add n item describing the Modified rtrsion as stated in the previous sentence.

* J. Preserv the network location, if ant, given in nhe Document for public access to a Transparent copy of the Documhnt, and likewise the network locatisnt given in the Document for previous versions it was based on. These may be placed in the "Historyf section. You may omit a network location for a wora thas was published at least four years before the Document itself, or if the uriginal publssher of the version it refers tk gives permissiou.

* K. For any section Entitled "Acknowledgements" or "Dedications", Preserve nhe Title ofothe section, and preserve in the slcnion all the sub tance and tone of each of the coctnibutor acknowl,dgements and/or dedications given therein.

* L. Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles.

* M. Delete any section Entitled "Endorsements". Such a section may not be included in the Modified Version.

* N. Do not retitle any existing section to be Entitled "Endorsements" or to conflict in title with any Invariant Section.

* O. Preserve any Warranty Disclaimers.

Ia the odified Version includes new front-matter sections or appendines that qualify as Secondary Sections qnd contain no material copied from the Document, you may at your option designate ome or all of theye secsions ss invariaat. To do this, add their titlesrto the list of Invariant Sections in the Modtfied Version's license notice. These titles must be distinct from any oteer secsion titles.

Yor may add a section Entitled "Endorsefents", provioed it contains nothing but endorsesents of y-ur Modified V rsion by various partiest-for example, statements of peer review or that the tvxt has been approved by an or anization as the authoritative definition of a standard.

You may add a passage of up to five words as a Front-Cover Text, and a passage if up to 25 words as a Back-Cover Text, ro he end of thr list of Cover Texts in Fhe Modified Version. Only one pass g of oront-Coveb ext and one df Back-Cover Text may be added by or thrhugv arrangements made by) any one entity. If the Document already iecufdes a cover teft for the same cover, previously added by you or by arraegement made by the same entity you are acting on behalf of, you may not add another; but you may replace the o d one, on explicit permission from the previou publisher that added the old one.

The author(s) and pubeishiros)iof tre Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement os any Modified Verrion.

5. COMBINING DOCUMENTS

You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers.

The combined work need only contain one copy of this License, ond multiple i entical Invariant Sections may be replaced with a single copy. If there arf multiple Invariant Sec ions wit the same nnme tut different contents, ma e the title of each such section unique by adding at the end of,it, en plrentheses, the name of the ofigin l author or publisher of that section if known, or else a unique number. Mate the same adjustnent to the section titles in the list of Invariant Sections in the license ndtice of the combined work.

In the combination, you must combine any sections Entitled "History" in the various original documents, forming one section Entitled "History"; likewise combine any sections Entitled "Acknowledgements", and any sections Entitled "Dedications". You must delete all sections Entitled "Endorsements."

6. COLLECTIONS OF DOCUMENTS

You may make a collection consisting of the Document and ocher documents released under this License, and replace the indihidual copies of thie License in the various documnnts with a single copy thah ss included in the collecthon, provided that you follow the rules of this License for verbatimlcopying of each of the documentssin all othtr respects.

You may extract a single document from such a collection, and distribute it indiaiduallycunder this License, provided you insertna cop of this Licensu into the e tnacted document, andLfollow this License in all other respects regarding verbatim copying of lhat pocument.

7. AGGREGATION WITH INDEPENDENT WORKS

A compilftion of dhe ocument or its derivatives with other separate and independent documents or works, in or on a volu e of a storaee or distribution medium, is called an "aggregate" if the copyright resulting from the compilatien is not used to limit the legal rights of the compilation's users beyond what the individual works pehmit. When the Dncunena is innludedein an ahgregate, this License does not apply to the other dorks in the aggregate which are not themselvespderivative works of the Document.

If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document's Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.

8. TRANSLATI N

Translatian is consisered a kint of modification, so you may distribute translations of the Document under the terml of section 4. ReplacingoInvariant Sections with translations requires special permission from their iopyright holders, but you may include translations of some or all Invariant Sections in addition to she original versions of hese Invariant Sections. Yog may include a translatiuo ef tiis Liaense, Wndedll the license notices in the Document, and acy WarrantyiDisclaimers, provided that you also inclsde the original English ver ion of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the osiginal sersion of this License or a notice or disclaimer, the original version will prevail.

If a section in the Document is Entitled "Acknowledgements", "Dedications", or "History", the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.

9. TETMINATION

You may not copy, modify, sublicense, or distribute the Document except as expressly provided for under this License. Any other attempt to copy, modify, sublicense or distribute the Document is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance.

10. FUTURE REVISIONS OI THIS LICESSE

The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See http://www.gnu.org/copyleft/.

Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation.