gfdl (1)





NAME

       GFDL - The GNU Free Documentation License

                               Version 1.1, March 2000

       Copyright (c) 2000  Free Software Foundation, Inc.  59 Temple Place,
       Suite 330, Boston, MA  02111-1307  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
       written document "free" in the sense of freedom: to assure everyone the
       effective  freedom to copy and redistribute it, with or without modify-
       ing it, either commercially or noncommercially.  Secondarily, this  Li-
       cense  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", which means that derivative works
       of the document must themselves be free in the same sense.  It  comple-
       ments  the  GNU General Public License, which is a copyleft license de-
       signed for free software.

       We have designed this License in order to use it for manuals  for  free
       software,  because  free software needs free documentation: a free pro-
       gram 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 License applies to any manual or other work that contains a notice
       placed  by  the copyright holder saying it can be distributed under the
       terms of this License.  The "Document", below, refers to any such manu-
       al  or  work.  Any member of the public is a licensee, and is addressed
       as "you."

       A "Modified Version" of the Document means any work containing the Doc-
       ument 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 pub-
       lishers 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.  (For example, 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 connec-
       tion with the subject or with related matters, or of legal, commercial,
       philosophical, ethical or political position regarding them.
       A "Transparent" copy of the Document  means  a  machine-readable  copy,
       represented in a format whose specification is available to the general
       public, whose contents can be viewed and edited directly and  straight-
       forwardly  with generic text editors or (for images composed of pixels)
       generic paint programs or (for drawings) some widely available  drawing
       editor,  and that is suitable for input to text formatters or for auto-
       matic translation to a variety of formats suitable for  input  to  text
       formatters.   A copy made in an otherwise Transparent file format whose
       markup has been designed to thwart or discourage  subsequent  modifica-
       tion  by  readers is not Transparent.  A copy that is not "Transparent"
       is called "Opaque."

       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 de-
       signed for human modification.  Opaque formats include PostScript, PDF,
       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 produced by
       some word processors for output purposes only.

       The "Title Page" means, for a printed book, the title page itself, plus
       such following pages as are needed to hold, legibly, the material  this
       License  requires  to  appear  in the title page.  For works in formats
       which do not have any title page as such, "Title Page" means  the  text
       near  the  most prominent appearance of the work's title, preceding the
       beginning of the body of the text.


2. VERBATIM COPYING

       You may copy and distribute the Document in any medium, either  commer-
       cially  or  noncommercially,  provided that this License, the copyright
       notices, and the license notice saying this License applies to the Doc-
       ument  are  reproduced  in all copies, and that you add no other condi-
       tions 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 copies, under the same conditions stated  above,  and
       you may publicly display copies.


3. COPYING IN QUANTITY

       If  you publish printed copies of the Document numbering more than 100,
       and the Document's license notice requires Cover Texts,  you  must  en-
       close  the  copies in covers that carry, clearly and legibly, all these
       Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts
       on  the back cover.  Both covers must also clearly and legibly identify
       you as the publisher of these copies.  The front cover must present the
       full  title  with all words of the title equally prominent and visible.
       You may add other material on the covers  in  addition.   Copying  with
       changes  limited  to  the covers, as long as they preserve the title of
       the Document and satisfy these conditions, can be treated  as  verbatim
       copying in other respects.

       general network-using public has access to download anonymously  at  no
       charge  using public-standard network protocols.  If you use the latter
       option, you must take reasonably prudent steps, when you begin  distri-
       bution  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 is requested, but not required, that you contact the authors of  the
       Document well before redistributing any large number of copies, to give
       them a chance to provide you with an updated version of the Document.


4. MODIFICATIONS

       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  Ver-
       sion  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 dis-
              tinct from that of the Document, and from those of previous ver-
              sions (which should, if there were any, be listed in the History
              section of the Document).  You may use the same title as a  pre-
              vious  version  if  the original publisher of that version gives
              permission.

       B.     List on the Title Page, as authors, one or more persons or enti-
              ties responsible for authorship of the modifications in the Mod-
              ified Version, together with at least five of the principal  au-
              thors  of  the Document (all of its principal authors, if it has
              less than five).

       C.     State on the Title page the name of the publisher of  the  Modi-
              fied Version, as the publisher.

       D.     Preserve all the copyright notices of the Document.

       E.     Add an appropriate copyright notice for your modifications adja-
              cent to the other copyright notices.

       F.     Include, immediately after the copyright notices, a license  no-
              tice  giving  the  public permission to use the Modified Version
              under the terms of this License, in the form shown in the Adden-
              dum below.

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

       H.     Include an unaltered copy of this License.

       I.     Preserve  the section entitled "History", and its title, and add
              to it an item stating at least the title, year, new authors, and
              publisher  of  the  Modified Version as given on the Title Page.
              If there is no section entitled "History" in the Document,  cre-
              published at least four years before the Document itself, or  if
              the original publisher of the version it refers to gives permis-
              sion.

       K.     In any section  entitled  "Acknowledgements"  or  "Dedications",
              preserve  the  section's  title, and preserve in the section all
              the substance and tone of each of the  contributor  acknowledge-
              ments 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 as "Endorsements" or to con-
              flict in title with any Invariant Section.

       If  the  Modified  Version includes new front-matter sections or appen-
       dices that qualify as Secondary Sections and contain no material copied
       from  the  Document,  you  may  at your option designate some or all of
       these sections as invariant.  To do this, add their titles to the  list
       of  Invariant Sections in the Modified Version's license notice.  These
       titles must be distinct from any other section titles.

       You may add a section entitled  "Endorsements",  provided  it  contains
       nothing  but  endorsements  of  your  Modified  Version by various par-
       ties--for example, statements of peer review or that the text has  been
       approved  by an organization as the authoritative definition of a stan-
       dard.

       You may add a passage of up to five words as a Front-Cover Text, and  a
       passage  of up to 25 words as a Back-Cover Text, to the end of the list
       of Cover Texts in the Modified Version.  Only one passage of Front-Cov-
       er Text and one of Back-Cover Text may be added by (or through arrange-
       ments made by) any one entity.  If the Document already includes a cov-
       er  text  for the same cover, previously added by you or by arrangement
       made by the same entity you are acting on behalf of, you  may  not  add
       another;  but  you may replace the old one, on explicit permission from
       the previous publisher that added the old one.

       The author(s) and publisher(s) of the Document do not by  this  License
       give  permission  to  use their names for publicity for or to assert or
       imply endorsement of any Modified Version.


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 ver-
       sions, provided that you include in the combination all of the  Invari-
       ant  Sections  of  all  of the original documents, unmodified, and list
       them all as Invariant Sections of your combined work in its license no-
       tice.

       The  combined work need only contain one copy of this License, and mul-
       tiple identical Invariant Sections may be replaced with a single  copy.
       likewise combine any sections entitled "Acknowledgements", and any sec-
       tions  entitled  "Dedications."   You must delete all sections entitled
       "Endorsements."


6. COLLECTIONS OF DOCUMENTS

       You may make a collection consisting of the Document  and  other  docu-
       ments released under this License, and replace the individual copies of
       this License in the various documents with a single copy  that  is  in-
       cluded  in  the  collection, provided that you follow the rules of this
       License for verbatim copying of each of the documents in all other  re-
       spects.

       You  may  extract  a  single  document from such a collection, and dis-
       tribute it individually under this License, provided you insert a  copy
       of this License into the extracted document, and follow this License in
       all other respects regarding verbatim copying of that document.


7. AGGREGATION WITH INDEPENDENT WORKS

       A compilation of the Document or its derivatives  with  other  separate
       and  independent  documents or works, in or on a volume of a storage or
       distribution medium, does not as a whole count as a Modified Version of
       the Document, provided no compilation copyright is claimed for the com-
       pilation.  Such a compilation is called an "aggregate",  and  this  Li-
       cense  does  not  apply to the other self-contained works thus compiled
       with the Document, on account of their being thus compiled, if they are
       not themselves derivative 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  quarter
       of  the  entire  aggregate, the Document's Cover Texts may be placed on
       covers that surround only the Document within the aggregate.  Otherwise
       they must appear on covers around the whole aggregate.


8. TRANSLATION

       Translation is considered a kind of modification, so you may distribute
       translations of the Document under the terms of section  4.   Replacing
       Invariant  Sections  with translations requires special permission from
       their copyright holders, but you may include translations  of  some  or
       all  Invariant  Sections  in addition to the original versions of these
       Invariant Sections.  You may include a translation of this License pro-
       vided  that  you  also include the original English version of this Li-
       cense.  In case of a disagreement between the translation and the orig-
       inal English version of this License, the original English version will
       prevail.


9. TERMINATION

       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, par-
       ties 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.
       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.


ADDENDUM: How to use this License for your documents

       To  use  this License in a document you have written, include a copy of
       the License in the document and put the following copyright and license
       notices just after the title page:

       Copyright (c) [year]  [your name].  Permission is granted to copy,
       distribute and/or modify this document under the terms of the GNU Free
       Documentation License, Version 1.1 or any later version published by
       the Free Software Foundation; with the Invariant Sections being [list
       their titles], with the Front-Cover Texts being [list], and with the
       Back-Cover Texts being [list].  A copy of the license is included in
       the section entitled "GNU Free Documentation License."

       If  you  have no Invariant Sections, write "with no Invariant Sections"
       instead of saying which ones are invariant.  If you have no Front-Cover
       Texts, write "no Front-Cover Texts" instead of "Front-Cover Texts being
       [list]"; likewise for Back-Cover Texts.

       If your document contains nontrivial examples of program code, we  rec-
       ommend  releasing  these examples in parallel under your choice of free
       software license, such as the GNU General  Public  License,  to  permit
       their use in free software.

4th Berkeley Distribution        2001 April 23                         gfdl(1)