                    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
    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", which means that derivative
    works of the document must themselves be free in the same sense.  It
    complements the GNU General Public License, which is a copyleft
    license designed 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
    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 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 manual 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
    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.  (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
    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.

    The "Cover Texts" are certain short passages of text that are listed,
    as Front-Cover Texts or Back-Cover Texts, in the notice that says that
    the Document is released under this License.

    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
    straightforwardly 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 automatic 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 modification 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 designed 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
    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 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 enclose
    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.

    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 publicly-accessible computer-network location containing a complete
    Transparent copy of the Document, free of added material, which the
    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
    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 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
    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 less than five).
    C. State on the Title page the name of the publisher of the
       Modified Version, as the publisher.
    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.
    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, create one
       stating the title, year, authors, and publisher of the Document as
       given on its Title Page, then add an item describing the Modified
       Version as stated in the previous sentence.
    J. Preserve the network location, if any, given in the Document for
       public access to a Transparent copy of the Document, and likewise
       the network locations given in the Document for previous versions
       it was based on.  These may be placed in the "History" section.
       You may omit a network location for a work that was published at
       least four years before the Document itself, or if the original
       publisher of the version it refers to gives permission.
    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 acknowledgements
       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 conflict in title with any Invariant Section.

    If the Modified Version includes new front-matter sections or
    appendices 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
    parties--for example, statements of peer review or that the text has
    been approved by an organization 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 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-Cover Text and one of Back-Cover Text may be added by (or
    through arrangements made by) any one entity.  If the Document already
    includes a cover 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
    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.

    The combined work need only contain one copy of this License, and
    multiple identical Invariant Sections may be replaced with a single
    copy.  If there are multiple Invariant Sections with the same name but
    different contents, make the title of each such section unique by
    adding at the end of it, in parentheses, the name of the original
    author or publisher of that section if known, or else a unique number.
    Make the same adjustment to the section titles in the list of
    Invariant Sections in the license notice 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 other documents
    released under this License, and replace the individual copies of this
    License in the various documents with a single copy that is included in
    the collection, provided that you follow the rules of this License for
    verbatim copying of each of the documents in all other respects.

    You may extract a single document from such a collection, and distribute
    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
    compilation.  Such a compilation is called an "aggregate", and this
    License 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 provided that you also include the
    original English version of this License.  In case of a disagreement
    between the translation and the original 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,
    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 OF THIS LICENSE

    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.

    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
    recommend 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.