Applicability and definitions
This License applies to any manual or other work, in any
medium, that contains a notice placed by the copyright holder
saying it can be distributed under the terms of this License.
Such a notice grants a world-wide, royalty-free license, unlimited
in duration, to use that work under the conditions stated herein.
The ``Document'', below, refers to any such manual or work. Any
member of the public is a licensee, and is addressed as ``you''.
You accept the license if you copy, modify or distribute the work
in a way requiring permission under copyright law.
A ``Modified Version'' of the Document means any work
containing the Document or a portion of it, either copied
verbatim, or with modifications and/or translated into another
language.
A ``Secondary Section'' is a named appendix or a
front-matter section of the Document that deals exclusively with
the relationship of the publishers or authors of the Document to
the Document's overall subject (or to related matters) and
contains nothing that could fall directly within that overall
subject. (Thus, if the Document is in part a textbook of
mathematics, a Secondary Section may not explain any mathematics.)
The relationship could be a matter of historical connection with
the subject or with related matters, or of legal, commercial,
philosophical, ethical or political position regarding
them.
The ``Invariant Sections'' are certain Secondary Sections
whose titles are designated, as being those of Invariant Sections,
in the notice that says that the Document is released under this
License. If a section does not fit the above definition of
Secondary then it is not allowed to be designated as Invariant.
The Document may contain zero Invariant Sections. If the Document
does not identify any Invariant Sections then there are
none.
The ``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 Front-Cover Text may be at most 5 words, and a Back-Cover Text
may be at most 25 words.
A ``Transparent'' copy of the Document means a
machine-readable copy, represented in a format whose specification
is available to the general public, that is suitable for revising
the document 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, or
absence of markup, has been arranged to thwart or discourage
subsequent modification by readers is not Transparent. An image
format is not Transparent if used for any substantial amount of
text. 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, PostScript or PDF designed for
human modification. Examples of transparent image formats include
PNG, XCF and JPG. Opaque formats include proprietary formats that
can be read and edited only by proprietary word processors, SGML
or XML for which the DTD and/or processing tools are not generally
available, and the machine-generated HTML, PostScript or PDF
produced by some word processors for output purposes only.
The ``Title Page'' means, for a printed 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.
A section ``Entitled XYZ'' means a named subunit of the
Document whose title either is precisely XYZ or contains XYZ in
parentheses following text that translates XYZ in another
language. (Here XYZ stands for a specific section name mentioned
below, such as ``Acknowledgements'', ``Dedications'',
``Endorsements'', or ``History''.) To ``Preserve the Title'' of
such a section when you modify the Document means that it remains
a section ``Entitled XYZ'' according to this definition.
The Document may include Warranty Disclaimers next to the
notice which states that this License applies to the Document.
These Warranty Disclaimers are considered to be included by
reference in this License, but only as regards disclaiming
warranties: any other implication that these Warranty Disclaimers
may have is void and has no effect on the meaning of this
License.