| 1 | GNU Free Documentation License | 
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| 2 | Version 1.2, November 2002 | 
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| 3 | Copyright (c) 2000,2001,2002 Free Software Foundation, Inc. | 
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| 4 | 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA | 
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| 5 |  | 
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| 6 | Everyone is permitted to copy and distribute verbatim copies | 
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| 7 | of this license document, but changing it is not allowed. | 
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| 8 |  | 
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| 9 |  0. PREAMBLE | 
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| 10 |  The purpose of this License is to make a manual, textbook, or other functional and | 
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| 11 |  useful document free in the sense of freedom: to assure everyone the effective freedom | 
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| 12 |  to copy and redistribute it, with or without modifying it, either commercially or noncommercially. | 
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| 13 |  Secondarily, this License preserves for the author and publisher a way | 
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| 14 |  to get credit for their work, while not being considered responsible for modifications | 
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| 15 |  made by others. | 
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| 16 |  This License is a kind of âcopyleftâ, which means that derivative works of the document | 
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| 17 |  must themselves be free in the same sense. It complements the GNU General Public | 
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| 18 |  License, which is a copyleft license designed for free software. | 
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| 19 |  We have designed this License in order to use it for manuals for free software, because | 
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| 20 |  free software needs free documentation: a free program should come with manuals | 
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| 21 |  providing the same freedoms that the software does. But this License is not limited to | 
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| 22 |  software manuals; it can be used for any textual work, regardless of subject matter or | 
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| 23 |  whether it is published as a printed book. We recommend this License principally for | 
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| 24 |  works whose purpose is instruction or reference. | 
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| 25 |  1. APPLICABILITY AND DEFINITIONS | 
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| 26 |  This License applies to any manual or other work, in any medium, that contains a | 
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| 27 |  notice placed by the copyright holder saying it can be distributed under the terms | 
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| 28 |  of this License. Such a notice grants a world-wide, royalty-free license, unlimited in | 
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| 29 |  duration, to use that work under the conditions stated herein. The âDocumentâ, | 
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| 30 |  below, refers to any such manual or work. Any member of the public is a licensee, and | 
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| 31 |  is addressed as âyouâ. You accept the license if you copy, modify or distribute the work | 
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| 32 |  in a way requiring permission under copyright law. | 
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| 33 |  A âModified Versionâ of the Document means any work containing the Document or | 
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| 34 |  a portion of it, either copied verbatim, or with modifications and/or translated into | 
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| 35 |  another language. | 
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| 36 |  A âSecondary Sectionâ is a named appendix or a front-matter section of the Document | 
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| 37 |  that deals exclusively with the relationship of the publishers or authors of the Document | 
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| 38 |  to the Documentâs overall subject (or to related matters) and contains nothing that | 
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| 39 |  could fall directly within that overall subject. (Thus, if the Document is in part a | 
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| 40 |  textbook of mathematics, a Secondary Section may not explain any mathematics.) The | 
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| 41 |  relationship could be a matter of historical connection with the subject or with related | 
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| 42 |  matters, or of legal, commercial, philosophical, ethical or political position regarding | 
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| 43 |  them. | 
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| 44 |  The âInvariant Sectionsâ are certain Secondary Sections whose titles are designated, as | 
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| 45 |  being those of Invariant Sections, in the notice that says that the Document is released | 
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| 46 |  under this License. If a section does not fit the above definition of Secondary then it is | 
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| 47 |  not allowed to be designated as Invariant. The Document may contain zero Invariant | 
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| 48 |  Sections. If the Document does not identify any Invariant Sections then there are none. | 
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| 49 |  The âCover Textsâ are certain short passages of text that are listed, as Front-Cover | 
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| 50 |  Texts or Back-Cover Texts, in the notice that says that the Document is released under | 
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| 51 |  this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may | 
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| 52 |  be at most 25 words. | 
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| 53 |  A âTransparentâ copy of the Document means a machine-readable copy, represented | 
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| 54 |  in a format whose specification is available to the general public, that is suitable for | 
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| 55 |  revising the document straightforwardly with generic text editors or (for images composed | 
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| 56 |  of pixels) generic paint programs or (for drawings) some widely available drawing | 
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| 57 |  editor, and that is suitable for input to text formatters or for automatic translation to | 
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| 58 |  a variety of formats suitable for input to text formatters. A copy made in an otherwise | 
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| 59 |  Transparent file format whose markup, or absence of markup, has been arranged to | 
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| 60 |  thwart or discourage subsequent modification by readers is not Transparent. An image | 
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| 61 |  format is not Transparent if used for any substantial amount of text. A copy that is | 
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| 62 |  not âTransparentâ is called âOpaqueâ. | 
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| 63 |  Examples of suitable formats for Transparent copies include plain ascii without | 
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| 64 |  markup, Texinfo input format, LaTEX input format, SGML or XML using a publicly | 
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| 65 |  available DTD, and standard-conforming simple HTML, PostScript or PDF designed | 
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| 66 |  for human modification. Examples of transparent image formats include PNG, XCF | 
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| 67 |  and JPG. Opaque formats include proprietary formats that can be read and edited | 
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| 68 |  only by proprietary word processors, SGML or XML for which the DTD and/or | 
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| 69 |  processing tools are not generally available, and the machine-generated HTML, | 
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| 70 |  PostScript or PDF produced by some word processors for output purposes only. | 
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| 71 |  The âTitle Pageâ means, for a printed book, the title page itself, plus such following | 
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| 72 |  pages as are needed to hold, legibly, the material this License requires to appear in the | 
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| 73 |  title page. For works in formats which do not have any title page as such, âTitle Pageâ | 
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| 74 |  means the text near the most prominent appearance of the workâs title, preceding the | 
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| 75 |  beginning of the body of the text. | 
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| 76 |  A section âEntitled XYZâ means a named subunit of the Document whose title either | 
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| 77 |  is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in | 
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| 78 |  another language. (Here XYZ stands for a specific section name mentioned below, such | 
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| 79 |  as âAcknowledgementsâ, âDedicationsâ, âEndorsementsâ, or âHistoryâ.) To âPreserve | 
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| 80 |  the Titleâ of such a section when you modify the Document means that it remains a | 
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| 81 |  section âEntitled XYZâ according to this definition. | 
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| 82 |  The Document may include Warranty Disclaimers next to the notice which states that | 
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| 83 |  this License applies to the Document. These Warranty Disclaimers are considered to | 
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| 84 |  be included by reference in this License, but only as regards disclaiming warranties: | 
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| 85 |  any other implication that these Warranty Disclaimers may have is void and has no | 
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| 86 |  effect on the meaning of this License. | 
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| 87 |  2. VERBATIM COPYING | 
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| 88 |  You may copy and distribute the Document in any medium, either commercially or | 
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| 89 |  noncommercially, provided that this License, the copyright notices, and the license | 
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| 90 |  notice saying this License applies to the Document are reproduced in all copies, and | 
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| 91 |  that you add no other conditions whatsoever to those of this License. You may not use | 
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| 92 |  technical measures to obstruct or control the reading or further copying of the copies | 
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| 93 |  you make or distribute. However, you may accept compensation in exchange for copies. | 
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| 94 |  If you distribute a large enough number of copies you must also follow the conditions | 
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| 95 |  in section 3. | 
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| 96 |  You may also lend copies, under the same conditions stated above, and you may publicly | 
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| 97 |  display copies. | 
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| 98 |  3. COPYING IN QUANTITY | 
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| 99 |  If you publish printed copies (or copies in media that commonly have printed covers) of | 
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| 100 |  the Document, numbering more than 100, and the Documentâs license notice requires | 
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| 101 |  Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all | 
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| 102 |  these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on | 
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| 103 |  the back cover. Both covers must also clearly and legibly identify you as the publisher | 
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| 104 |  of these copies. The front cover must present the full title with all words of the title | 
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| 105 |  equally prominent and visible. You may add other material on the covers in addition. | 
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| 106 |  Copying with changes limited to the covers, as long as they preserve the title of the | 
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| 107 |  Document and satisfy these conditions, can be treated as verbatim copying in other | 
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| 108 |  respects. | 
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| 109 |  If the required texts for either cover are too voluminous to fit legibly, you should put | 
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| 110 |  the first ones listed (as many as fit reasonably) on the actual cover, and continue the | 
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| 111 |  rest onto adjacent pages. | 
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| 112 |  If you publish or distribute Opaque copies of the Document numbering more than 100, | 
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| 113 |  you must either include a machine-readable Transparent copy along with each Opaque | 
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| 114 |  copy, or state in or with each Opaque copy a computer-network location from which | 
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| 115 |  the general network-using public has access to download using public-standard network | 
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| 116 |  protocols a complete Transparent copy of the Document, free of added material. If | 
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| 117 |  you use the latter option, you must take reasonably prudent steps, when you begin | 
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| 118 |  distribution of Opaque copies in quantity, to ensure that this Transparent copy will | 
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| 119 |  remain thus accessible at the stated location until at least one year after the last time | 
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| 120 |  you distribute an Opaque copy (directly or through your agents or retailers) of that | 
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| 121 |  edition to the public. | 
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| 122 |  It is requested, but not required, that you contact the authors of the Document well | 
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| 123 |  before redistributing any large number of copies, to give them a chance to provide you | 
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| 124 |  with an updated version of the Document. | 
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| 125 |  4. MODIFICATIONS | 
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| 126 |  You may copy and distribute a Modified Version of the Document under the conditions | 
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| 127 |  of sections 2 and 3 above, provided that you release the Modified Version under precisely | 
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| 128 |  this License, with the Modified Version filling the role of the Document, thus licensing | 
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| 129 |  distribution and modification of the Modified Version to whoever possesses a copy of | 
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| 130 |  it. In addition, you must do these things in the Modified Version: | 
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| 131 |  A. Use in the Title Page (and on the covers, if any) a title distinct from that of the | 
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| 132 |  Document, and from those of previous versions (which should, if there were any, | 
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| 133 |  be listed in the History section of the Document). You may use the same title as | 
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| 134 |  a previous version if the original publisher of that version gives permission. | 
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| 135 |  B. List on the Title Page, as authors, one or more persons or entities responsible for | 
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| 136 |  authorship of the modifications in the Modified Version, together with at least five | 
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| 137 |  of the principal authors of the Document (all of its principal authors, if it has fewer | 
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| 138 |  than five), unless they release you from this requirement. | 
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| 139 |  C. State on the Title page the name of the publisher of the Modified Version, as the | 
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| 140 |  publisher. | 
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| 141 |  D. Preserve all the copyright notices of the Document. | 
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| 142 |  E. Add an appropriate copyright notice for your modifications adjacent to the other | 
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| 143 |  copyright notices. | 
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| 144 |  F. Include, immediately after the copyright notices, a license notice giving the public | 
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| 145 |  permission to use the Modified Version under the terms of this License, in the form | 
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| 146 |  shown in the Addendum below. | 
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| 147 |  G. Preserve in that license notice the full lists of Invariant Sections and required Cover | 
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| 148 |  Texts given in the Documentâs license notice. | 
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| 149 |  H. Include an unaltered copy of this License. | 
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| 150 |  I. Preserve the section Entitled âHistoryâ, Preserve its Title, and add to it an item | 
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| 151 |  stating at least the title, year, new authors, and publisher of the Modified Version | 
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| 152 |  as given on the Title Page. If there is no section Entitled âHistoryâ in the Document, | 
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| 153 |  create one stating the title, year, authors, and publisher of the Document | 
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| 154 |  as given on its Title Page, then add an item describing the Modified Version as | 
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| 155 |  stated in the previous sentence. | 
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| 156 |  J. Preserve the network location, if any, given in the Document for public access to | 
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| 157 |  a Transparent copy of the Document, and likewise the network locations given in | 
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| 158 |  the Document for previous versions it was based on. These may be placed in the | 
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| 159 |  âHistoryâ section. You may omit a network location for a work that was published | 
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| 160 |  at least four years before the Document itself, or if the original publisher of the | 
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| 161 |  version it refers to gives permission. | 
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| 162 |  K. For any section Entitled âAcknowledgementsâ or âDedicationsâ, Preserve the Title | 
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| 163 |  of the section, and preserve in the section all the substance and tone of each of the | 
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| 164 |  contributor acknowledgements and/or dedications given therein. | 
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| 165 |  L. Preserve all the Invariant Sections of the Document, unaltered in their text and | 
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| 166 |  in their titles. Section numbers or the equivalent are not considered part of the | 
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| 167 |  section titles. | 
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| 168 |  M. Delete any section Entitled âEndorsementsâ. Such a section may not be included | 
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| 169 |  in the Modified Version. | 
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| 170 |  N. Do not retitle any existing section to be Entitled âEndorsementsâ or to conflict in | 
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| 171 |  title with any Invariant Section. | 
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| 172 |  O. Preserve any Warranty Disclaimers. | 
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| 173 |  If the Modified Version includes new front-matter sections or appendices that qualify | 
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| 174 |  as Secondary Sections and contain no material copied from the Document, you may at | 
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| 175 |  your option designate some or all of these sections as invariant. To do this, add their | 
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| 176 |  titles to the list of Invariant Sections in the Modified Versionâs license notice. These | 
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| 177 |  titles must be distinct from any other section titles. | 
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| 178 |  You may add a section Entitled âEndorsementsâ, provided it contains nothing but | 
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| 179 |  endorsements of your Modified Version by various partiesâfor example, statements of | 
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| 180 |  peer review or that the text has been approved by an organization as the authoritative | 
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| 181 |  definition of a standard. | 
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| 182 |  You may add a passage of up to five words as a Front-Cover Text, and a passage of up | 
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| 183 |  to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified | 
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| 184 |  Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be | 
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| 185 |  added by (or through arrangements made by) any one entity. If the Document already | 
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| 186 |  includes a cover text for the same cover, previously added by you or by arrangement | 
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| 187 |  made by the same entity you are acting on behalf of, you may not add another; but | 
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| 188 |  you may replace the old one, on explicit permission from the previous publisher that | 
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| 189 |  added the old one. | 
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| 190 |  The author(s) and publisher(s) of the Document do not by this License give permission | 
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| 191 |  to use their names for publicity for or to assert or imply endorsement of any Modified | 
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| 192 |  Version. | 
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| 193 |  5. COMBINING DOCUMENTS | 
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| 194 |  You may combine the Document with other documents released under this License, | 
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| 195 |  under the terms defined in section 4 above for modified versions, provided that you | 
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| 196 |  include in the combination all of the Invariant Sections of all of the original documents, | 
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| 197 |  unmodified, and list them all as Invariant Sections of your combined work in its license | 
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| 198 |  notice, and that you preserve all their Warranty Disclaimers. | 
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| 199 |  The combined work need only contain one copy of this License, and multiple identical | 
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| 200 |  Invariant Sections may be replaced with a single copy. If there are multiple Invariant | 
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| 201 |  Sections with the same name but different contents, make the title of each such section | 
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| 202 |  unique by adding at the end of it, in parentheses, the name of the original author or | 
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| 203 |  publisher of that section if known, or else a unique number. Make the same adjustment | 
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| 204 |  to the section titles in the list of Invariant Sections in the license notice of the combined | 
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| 205 |  work. | 
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| 206 |  In the combination, you must combine any sections Entitled âHistoryâ in the various | 
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| 207 |  original documents, forming one section Entitled âHistoryâ; likewise combine any | 
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| 208 |  sections Entitled âAcknowledgementsâ, and any sections Entitled âDedicationsâ. You | 
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| 209 |  must delete all sections Entitled âEndorsements.â | 
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| 210 |  6. COLLECTIONS OF DOCUMENTS | 
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| 211 |  You may make a collection consisting of the Document and other documents released | 
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| 212 |  under this License, and replace the individual copies of this License in the various | 
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| 213 |  documents with a single copy that is included in the collection, provided that you | 
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| 214 |  follow the rules of this License for verbatim copying of each of the documents in all | 
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| 215 |  other respects. | 
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| 216 |  You may extract a single document from such a collection, and distribute it individually | 
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| 217 |  under this License, provided you insert a copy of this License into the extracted | 
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| 218 |  document, and follow this License in all other respects regarding verbatim copying of | 
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| 219 |  that document. | 
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| 220 |  7. AGGREGATION WITH INDEPENDENT WORKS | 
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| 221 |  A compilation of the Document or its derivatives with other separate and independent | 
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| 222 |  documents or works, in or on a volume of a storage or distribution medium, is called | 
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| 223 |  an âaggregateâ if the copyright resulting from the compilation is not used to limit the | 
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| 224 |  legal rights of the compilationâs users beyond what the individual works permit. When | 
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| 225 |  the Document is included in an aggregate, this License does not apply to the other | 
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| 226 |  works in the aggregate which are not themselves derivative works of the Document. | 
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| 227 |  If the Cover Text requirement of section 3 is applicable to these copies of the Document, | 
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| 228 |  then if the Document is less than one half of the entire aggregate, the Documentâs Cover | 
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| 229 |  Texts may be placed on covers that bracket the Document within the aggregate, or the | 
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| 230 |  electronic equivalent of covers if the Document is in electronic form. Otherwise they | 
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| 231 |  must appear on printed covers that bracket the whole aggregate. | 
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| 232 |  8. TRANSLATION | 
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| 233 |  Translation is considered a kind of modification, so you may distribute translations | 
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| 234 |  of the Document under the terms of section 4. Replacing Invariant Sections with | 
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| 235 |  translations requires special permission from their copyright holders, but you may | 
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| 236 |  include translations of some or all Invariant Sections in addition to the original versions | 
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| 237 |  of these Invariant Sections. You may include a translation of this License, and all the | 
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| 238 |  license notices in the Document, and any Warranty Disclaimers, provided that you | 
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| 239 |  also include the original English version of this License and the original versions of | 
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| 240 |  those notices and disclaimers. In case of a disagreement between the translation and | 
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| 241 |  the original version of this License or a notice or disclaimer, the original version will | 
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| 242 |  prevail. | 
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| 243 |  If a section in the Document is Entitled âAcknowledgementsâ, âDedicationsâ, or âHistoryâ, | 
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| 244 |  the requirement (section 4) to Preserve its Title (section 1) will typically require | 
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| 245 |  changing the actual title. | 
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| 246 |  9. TERMINATION | 
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| 247 |  You may not copy, modify, sublicense, or distribute the Document except as expressly | 
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| 248 |  provided for under this License. Any other attempt to copy, modify, sublicense or | 
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| 249 |  distribute the Document is void, and will automatically terminate your rights under | 
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| 250 |  this License. However, parties who have received copies, or rights, from you under this | 
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| 251 |  License will not have their licenses terminated so long as such parties remain in full | 
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| 252 |  compliance. | 
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| 253 |  10. FUTURE REVISIONS OF THIS LICENSE | 
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| 254 |  The Free Software Foundation may publish new, revised versions of the GNU Free | 
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| 255 |  Documentation License from time to time. Such new versions will be similar in spirit | 
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| 256 |  to the present version, but may differ in detail to address new problems or concerns. | 
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| 257 |  See http://www.gnu.org/copyleft/. | 
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| 258 |  Each version of the License is given a distinguishing version number. If the Document | 
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| 259 |  specifies that a particular numbered version of this License âor any later versionâ | 
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| 260 |  applies to it, you have the option of following the terms and conditions either of that | 
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| 261 |  specified version or of any later version that has been published (not as a draft) by | 
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| 262 |  the Free Software Foundation. If the Document does not specify a version number of | 
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| 263 |  this License, you may choose any version ever published (not as a draft) by the Free | 
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| 264 |  Software Foundation. | 
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