FDL revision 8604c676
1                GNU Free Documentation License
2                 Version 1.3, 3 November 2008
3
4
5 Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
6     <http://fsf.org/>
7 Everyone is permitted to copy and distribute verbatim copies
8 of this license document, but changing it is not allowed.
9
100. PREAMBLE
11
12The purpose of this License is to make a manual, textbook, or other
13functional and useful document "free" in the sense of freedom: to
14assure everyone the effective freedom to copy and redistribute it,
15with or without modifying it, either commercially or noncommercially.
16Secondarily, this License preserves for the author and publisher a way
17to get credit for their work, while not being considered responsible
18for modifications made by others.
19
20This License is a kind of "copyleft", which means that derivative
21works of the document must themselves be free in the same sense.  It
22complements the GNU General Public License, which is a copyleft
23license designed for free software.
24
25We have designed this License in order to use it for manuals for free
26software, because free software needs free documentation: a free
27program should come with manuals providing the same freedoms that the
28software does.  But this License is not limited to software manuals;
29it can be used for any textual work, regardless of subject matter or
30whether it is published as a printed book.  We recommend this License
31principally for works whose purpose is instruction or reference.
32
33
341. APPLICABILITY AND DEFINITIONS
35
36This License applies to any manual or other work, in any medium, that
37contains a notice placed by the copyright holder saying it can be
38distributed under the terms of this License.  Such a notice grants a
39world-wide, royalty-free license, unlimited in duration, to use that
40work under the conditions stated herein.  The "Document", below,
41refers to any such manual or work.  Any member of the public is a
42licensee, and is addressed as "you".  You accept the license if you
43copy, modify or distribute the work in a way requiring permission
44under copyright law.
45
46A "Modified Version" of the Document means any work containing the
47Document or a portion of it, either copied verbatim, or with
48modifications and/or translated into another language.
49
50A "Secondary Section" is a named appendix or a front-matter section of
51the Document that deals exclusively with the relationship of the
52publishers or authors of the Document to the Document's overall
53subject (or to related matters) and contains nothing that could fall
54directly within that overall subject.  (Thus, if the Document is in
55part a textbook of mathematics, a Secondary Section may not explain
56any mathematics.)  The relationship could be a matter of historical
57connection with the subject or with related matters, or of legal,
58commercial, philosophical, ethical or political position regarding
59them.
60
61The "Invariant Sections" are certain Secondary Sections whose titles
62are designated, as being those of Invariant Sections, in the notice
63that says that the Document is released under this License.  If a
64section does not fit the above definition of Secondary then it is not
65allowed to be designated as Invariant.  The Document may contain zero
66Invariant Sections.  If the Document does not identify any Invariant
67Sections then there are none.
68
69The "Cover Texts" are certain short passages of text that are listed,
70as Front-Cover Texts or Back-Cover Texts, in the notice that says that
71the Document is released under this License.  A Front-Cover Text may
72be at most 5 words, and a Back-Cover Text may be at most 25 words.
73
74A "Transparent" copy of the Document means a machine-readable copy,
75represented in a format whose specification is available to the
76general public, that is suitable for revising the document
77straightforwardly with generic text editors or (for images composed of
78pixels) generic paint programs or (for drawings) some widely available
79drawing editor, and that is suitable for input to text formatters or
80for automatic translation to a variety of formats suitable for input
81to text formatters.  A copy made in an otherwise Transparent file
82format whose markup, or absence of markup, has been arranged to thwart
83or discourage subsequent modification by readers is not Transparent.
84An image format is not Transparent if used for any substantial amount
85of text.  A copy that is not "Transparent" is called "Opaque".
86
87Examples of suitable formats for Transparent copies include plain
88ASCII without markup, Texinfo input format, LaTeX input format, SGML
89or XML using a publicly available DTD, and standard-conforming simple
90HTML, PostScript or PDF designed for human modification.  Examples of
91transparent image formats include PNG, XCF and JPG.  Opaque formats
92include proprietary formats that can be read and edited only by
93proprietary word processors, SGML or XML for which the DTD and/or
94processing tools are not generally available, and the
95machine-generated HTML, PostScript or PDF produced by some word
96processors for output purposes only.
97
98The "Title Page" means, for a printed book, the title page itself,
99plus such following pages as are needed to hold, legibly, the material
100this License requires to appear in the title page.  For works in
101formats which do not have any title page as such, "Title Page" means
102the text near the most prominent appearance of the work's title,
103preceding the beginning of the body of the text.
104
105The "publisher" means any person or entity that distributes copies of
106the Document to the public.
107
108A section "Entitled XYZ" means a named subunit of the Document whose
109title either is precisely XYZ or contains XYZ in parentheses following
110text that translates XYZ in another language.  (Here XYZ stands for a
111specific section name mentioned below, such as "Acknowledgements",
112"Dedications", "Endorsements", or "History".)  To "Preserve the Title"
113of such a section when you modify the Document means that it remains a
114section "Entitled XYZ" according to this definition.
115
116The Document may include Warranty Disclaimers next to the notice which
117states that this License applies to the Document.  These Warranty
118Disclaimers are considered to be included by reference in this
119License, but only as regards disclaiming warranties: any other
120implication that these Warranty Disclaimers may have is void and has
121no effect on the meaning of this License.
122
1232. VERBATIM COPYING
124
125You may copy and distribute the Document in any medium, either
126commercially or noncommercially, provided that this License, the
127copyright notices, and the license notice saying this License applies
128to the Document are reproduced in all copies, and that you add no
129other conditions whatsoever to those of this License.  You may not use
130technical measures to obstruct or control the reading or further
131copying of the copies you make or distribute.  However, you may accept
132compensation in exchange for copies.  If you distribute a large enough
133number of copies you must also follow the conditions in section 3.
134
135You may also lend copies, under the same conditions stated above, and
136you may publicly display copies.
137
138
1393. COPYING IN QUANTITY
140
141If you publish printed copies (or copies in media that commonly have
142printed covers) of the Document, numbering more than 100, and the
143Document's license notice requires Cover Texts, you must enclose the
144copies in covers that carry, clearly and legibly, all these Cover
145Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on
146the back cover.  Both covers must also clearly and legibly identify
147you as the publisher of these copies.  The front cover must present
148the full title with all words of the title equally prominent and
149visible.  You may add other material on the covers in addition.
150Copying with changes limited to the covers, as long as they preserve
151the title of the Document and satisfy these conditions, can be treated
152as verbatim copying in other respects.
153
154If the required texts for either cover are too voluminous to fit
155legibly, you should put the first ones listed (as many as fit
156reasonably) on the actual cover, and continue the rest onto adjacent
157pages.
158
159If you publish or distribute Opaque copies of the Document numbering
160more than 100, you must either include a machine-readable Transparent
161copy along with each Opaque copy, or state in or with each Opaque copy
162a computer-network location from which the general network-using
163public has access to download using public-standard network protocols
164a complete Transparent copy of the Document, free of added material.
165If you use the latter option, you must take reasonably prudent steps,
166when you begin distribution of Opaque copies in quantity, to ensure
167that this Transparent copy will remain thus accessible at the stated
168location until at least one year after the last time you distribute an
169Opaque copy (directly or through your agents or retailers) of that
170edition to the public.
171
172It is requested, but not required, that you contact the authors of the
173Document well before redistributing any large number of copies, to
174give them a chance to provide you with an updated version of the
175Document.
176
177
1784. MODIFICATIONS
179
180You may copy and distribute a Modified Version of the Document under
181the conditions of sections 2 and 3 above, provided that you release
182the Modified Version under precisely this License, with the Modified
183Version filling the role of the Document, thus licensing distribution
184and modification of the Modified Version to whoever possesses a copy
185of it.  In addition, you must do these things in the Modified Version:
186
187A. Use in the Title Page (and on the covers, if any) a title distinct
188   from that of the Document, and from those of previous versions
189   (which should, if there were any, be listed in the History section
190   of the Document).  You may use the same title as a previous version
191   if the original publisher of that version gives permission.
192B. List on the Title Page, as authors, one or more persons or entities
193   responsible for authorship of the modifications in the Modified
194   Version, together with at least five of the principal authors of the
195   Document (all of its principal authors, if it has fewer than five),
196   unless they release you from this requirement.
197C. State on the Title page the name of the publisher of the
198   Modified Version, as the publisher.
199D. Preserve all the copyright notices of the Document.
200E. Add an appropriate copyright notice for your modifications
201   adjacent to the other copyright notices.
202F. Include, immediately after the copyright notices, a license notice
203   giving the public permission to use the Modified Version under the
204   terms of this License, in the form shown in the Addendum below.
205G. Preserve in that license notice the full lists of Invariant Sections
206   and required Cover Texts given in the Document's license notice.
207H. Include an unaltered copy of this License.
208I. Preserve the section Entitled "History", Preserve its Title, and add
209   to it an item stating at least the title, year, new authors, and
210   publisher of the Modified Version as given on the Title Page.  If
211   there is no section Entitled "History" in the Document, create one
212   stating the title, year, authors, and publisher of the Document as
213   given on its Title Page, then add an item describing the Modified
214   Version as stated in the previous sentence.
215J. Preserve the network location, if any, given in the Document for
216   public access to a Transparent copy of the Document, and likewise
217   the network locations given in the Document for previous versions
218   it was based on.  These may be placed in the "History" section.
219   You may omit a network location for a work that was published at
220   least four years before the Document itself, or if the original
221   publisher of the version it refers to gives permission.
222K. For any section Entitled "Acknowledgements" or "Dedications",
223   Preserve the Title of the section, and preserve in the section all
224   the substance and tone of each of the contributor acknowledgements
225   and/or dedications given therein.
226L. Preserve all the Invariant Sections of the Document,
227   unaltered in their text and in their titles.  Section numbers
228   or the equivalent are not considered part of the section titles.
229M. Delete any section Entitled "Endorsements".  Such a section
230   may not be included in the Modified Version.
231N. Do not retitle any existing section to be Entitled "Endorsements"
232   or to conflict in title with any Invariant Section.
233O. Preserve any Warranty Disclaimers.
234
235If the Modified Version includes new front-matter sections or
236appendices that qualify as Secondary Sections and contain no material
237copied from the Document, you may at your option designate some or all
238of these sections as invariant.  To do this, add their titles to the
239list of Invariant Sections in the Modified Version's license notice.
240These titles must be distinct from any other section titles.
241
242You may add a section Entitled "Endorsements", provided it contains
243nothing but endorsements of your Modified Version by various
244parties--for example, statements of peer review or that the text has
245been approved by an organization as the authoritative definition of a
246standard.
247
248You may add a passage of up to five words as a Front-Cover Text, and a
249passage of up to 25 words as a Back-Cover Text, to the end of the list
250of Cover Texts in the Modified Version.  Only one passage of
251Front-Cover Text and one of Back-Cover Text may be added by (or
252through arrangements made by) any one entity.  If the Document already
253includes a cover text for the same cover, previously added by you or
254by arrangement made by the same entity you are acting on behalf of,
255you may not add another; but you may replace the old one, on explicit
256permission from the previous publisher that added the old one.
257
258The author(s) and publisher(s) of the Document do not by this License
259give permission to use their names for publicity for or to assert or
260imply endorsement of any Modified Version.
261
262
2635. COMBINING DOCUMENTS
264
265You may combine the Document with other documents released under this
266License, under the terms defined in section 4 above for modified
267versions, provided that you include in the combination all of the
268Invariant Sections of all of the original documents, unmodified, and
269list them all as Invariant Sections of your combined work in its
270license notice, and that you preserve all their Warranty Disclaimers.
271
272The combined work need only contain one copy of this License, and
273multiple identical Invariant Sections may be replaced with a single
274copy.  If there are multiple Invariant Sections with the same name but
275different contents, make the title of each such section unique by
276adding at the end of it, in parentheses, the name of the original
277author or publisher of that section if known, or else a unique number.
278Make the same adjustment to the section titles in the list of
279Invariant Sections in the license notice of the combined work.
280
281In the combination, you must combine any sections Entitled "History"
282in the various original documents, forming one section Entitled
283"History"; likewise combine any sections Entitled "Acknowledgements",
284and any sections Entitled "Dedications".  You must delete all sections
285Entitled "Endorsements".
286
287
2886. COLLECTIONS OF DOCUMENTS
289
290You may make a collection consisting of the Document and other
291documents released under this License, and replace the individual
292copies of this License in the various documents with a single copy
293that is included in the collection, provided that you follow the rules
294of this License for verbatim copying of each of the documents in all
295other respects.
296
297You may extract a single document from such a collection, and
298distribute it individually under this License, provided you insert a
299copy of this License into the extracted document, and follow this
300License in all other respects regarding verbatim copying of that
301document.
302
303
3047. AGGREGATION WITH INDEPENDENT WORKS
305
306A compilation of the Document or its derivatives with other separate
307and independent documents or works, in or on a volume of a storage or
308distribution medium, is called an "aggregate" if the copyright
309resulting from the compilation is not used to limit the legal rights
310of the compilation's users beyond what the individual works permit.
311When the Document is included in an aggregate, this License does not
312apply to the other works in the aggregate which are not themselves
313derivative works of the Document.
314
315If the Cover Text requirement of section 3 is applicable to these
316copies of the Document, then if the Document is less than one half of
317the entire aggregate, the Document's Cover Texts may be placed on
318covers that bracket the Document within the aggregate, or the
319electronic equivalent of covers if the Document is in electronic form.
320Otherwise they must appear on printed covers that bracket the whole
321aggregate.
322
323
3248. TRANSLATION
325
326Translation is considered a kind of modification, so you may
327distribute translations of the Document under the terms of section 4.
328Replacing Invariant Sections with translations requires special
329permission from their copyright holders, but you may include
330translations of some or all Invariant Sections in addition to the
331original versions of these Invariant Sections.  You may include a
332translation of this License, and all the license notices in the
333Document, and any Warranty Disclaimers, provided that you also include
334the original English version of this License and the original versions
335of those notices and disclaimers.  In case of a disagreement between
336the translation and the original version of this License or a notice
337or disclaimer, the original version will prevail.
338
339If a section in the Document is Entitled "Acknowledgements",
340"Dedications", or "History", the requirement (section 4) to Preserve
341its Title (section 1) will typically require changing the actual
342title.
343
344
3459. TERMINATION
346
347You may not copy, modify, sublicense, or distribute the Document
348except as expressly provided under this License.  Any attempt
349otherwise to copy, modify, sublicense, or distribute it is void, and
350will automatically terminate your rights under this License.
351
352However, if you cease all violation of this License, then your license
353from a particular copyright holder is reinstated (a) provisionally,
354unless and until the copyright holder explicitly and finally
355terminates your license, and (b) permanently, if the copyright holder
356fails to notify you of the violation by some reasonable means prior to
35760 days after the cessation.
358
359Moreover, your license from a particular copyright holder is
360reinstated permanently if the copyright holder notifies you of the
361violation by some reasonable means, this is the first time you have
362received notice of violation of this License (for any work) from that
363copyright holder, and you cure the violation prior to 30 days after
364your receipt of the notice.
365
366Termination of your rights under this section does not terminate the
367licenses of parties who have received copies or rights from you under
368this License.  If your rights have been terminated and not permanently
369reinstated, receipt of a copy of some or all of the same material does
370not give you any rights to use it.
371
372
37310. FUTURE REVISIONS OF THIS LICENSE
374
375The Free Software Foundation may publish new, revised versions of the
376GNU Free Documentation License from time to time.  Such new versions
377will be similar in spirit to the present version, but may differ in
378detail to address new problems or concerns.  See
379http://www.gnu.org/copyleft/.
380
381Each version of the License is given a distinguishing version number.
382If the Document specifies that a particular numbered version of this
383License "or any later version" applies to it, you have the option of
384following the terms and conditions either of that specified version or
385of any later version that has been published (not as a draft) by the
386Free Software Foundation.  If the Document does not specify a version
387number of this License, you may choose any version ever published (not
388as a draft) by the Free Software Foundation.  If the Document
389specifies that a proxy can decide which future versions of this
390License can be used, that proxy's public statement of acceptance of a
391version permanently authorizes you to choose that version for the
392Document.
393
39411. RELICENSING
395
396"Massive Multiauthor Collaboration Site" (or "MMC Site") means any
397World Wide Web server that publishes copyrightable works and also
398provides prominent facilities for anybody to edit those works.  A
399public wiki that anybody can edit is an example of such a server.  A
400"Massive Multiauthor Collaboration" (or "MMC") contained in the site
401means any set of copyrightable works thus published on the MMC site.
402
403"CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 
404license published by Creative Commons Corporation, a not-for-profit 
405corporation with a principal place of business in San Francisco, 
406California, as well as future copyleft versions of that license 
407published by that same organization.
408
409"Incorporate" means to publish or republish a Document, in whole or in 
410part, as part of another Document.
411
412An MMC is "eligible for relicensing" if it is licensed under this 
413License, and if all works that were first published under this License 
414somewhere other than this MMC, and subsequently incorporated in whole or 
415in part into the MMC, (1) had no cover texts or invariant sections, and 
416(2) were thus incorporated prior to November 1, 2008.
417
418The operator of an MMC Site may republish an MMC contained in the site
419under CC-BY-SA on the same site at any time before August 1, 2009,
420provided the MMC is eligible for relicensing.
421
422
423ADDENDUM: How to use this License for your documents
424
425To use this License in a document you have written, include a copy of
426the License in the document and put the following copyright and
427license notices just after the title page:
428
429    Copyright (c)  YEAR  YOUR NAME.
430    Permission is granted to copy, distribute and/or modify this document
431    under the terms of the GNU Free Documentation License, Version 1.3
432    or any later version published by the Free Software Foundation;
433    with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
434    A copy of the license is included in the section entitled "GNU
435    Free Documentation License".
436
437If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
438replace the "with...Texts." line with this:
439
440    with the Invariant Sections being LIST THEIR TITLES, with the
441    Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
442
443If you have Invariant Sections without Cover Texts, or some other
444combination of the three, merge those two alternatives to suit the
445situation.
446
447If your document contains nontrivial examples of program code, we
448recommend releasing these examples in parallel under your choice of
449free software license, such as the GNU General Public License,
450to permit their use in free software.
451