License.txt

----------------------------------------------------------------------
The ANN Library (all versions) is provided under the terms and
conditions of the GNU Lesser General Public Library, which is stated
below.  It can also be found at:

   http://www.gnu.org/copyleft/lesser.html

----------------------------------------------------------------------

GNU LESSER GENERAL PUBLIC LICENSE

Version 2.1, February 1999

Copyright (C) 1991, 1999 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.

[This is the first released version of the Lesser GPL.  It also counts
as the successor of the GNU Library Public License, version 2, hence the
version number 2.1.]

Preamble

The licenses for most software are designed to take away your freedom to
share and change it. By contrast, the GNU General Public Licenses are
intended to guarantee your freedom to share and change free software--to
make sure the software is free for all its users.

This license, the Lesser General Public License, applies to some
specially designated software packages--typically libraries--of the Free
Software Foundation and other authors who decide to use it. You can use
it too, but we suggest you first think carefully about whether this
license or the ordinary General Public License is the better strategy to
use in any particular case, based on the explanations below.

When we speak of free software, we are referring to freedom of use, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish); that you receive source code or can get it if
you want it; that you can change the software and use pieces of it in
new free programs; and that you are informed that you can do these
things.

To protect your rights, we need to make restrictions that forbid
distributors to deny you these rights or to ask you to surrender these
rights. These restrictions translate to certain responsibilities for you
if you distribute copies of the library or if you modify it.

For example, if you distribute copies of the library, whether gratis or
for a fee, you must give the recipients all the rights that we gave you.
You must make sure that they, too, receive or can get the source code.
If you link other code with the library, you must provide complete
object files to the recipients, so that they can relink them with the
library after making changes to the library and recompiling it. And you
must show them these terms so they know their rights.

We protect your rights with a two-step method: (1) we copyright the
library, and (2) we offer you this license, which gives you legal
permission to copy, distribute and/or modify the library.

To protect each distributor, we want to make it very clear that there is
no warranty for the free library. Also, if the library is modified by
someone else and passed on, the recipients should know that what they
have is not the original version, so that the original author's
reputation will not be affected by problems that might be introduced by
others.

Finally, software patents pose a constant threat to the existence of any
free program. We wish to make sure that a company cannot effectively
restrict the users of a free program by obtaining a restrictive license
from a patent holder. Therefore, we insist that any patent license
obtained for a version of the library must be consistent with the full
freedom of use specified in this license.

Most GNU software, including some libraries, is covered by the ordinary
GNU General Public License. This license, the GNU Lesser General Public
License, applies to certain designated libraries, and is quite different
from the ordinary General Public License. We use this license for
certain libraries in order to permit linking those libraries into
non-free programs.

When a program is linked with a library, whether statically or using a
shared library, the combination of the two is legally speaking a
combined work, a derivative of the original library. The ordinary
General Public License therefore permits such linking only if the entire
combination fits its criteria of freedom. The Lesser General Public
License permits more lax criteria for linking other code with the
library.

We call this license the "Lesser" General Public License because it does
Less to protect the user's freedom than the ordinary General Public
License. It also provides other free software developers Less of an
advantage over competing non-free programs. These disadvantages are the
reason we use the ordinary General Public License for many libraries.
However, the Lesser license provides advantages in certain special
circumstances.

For example, on rare occasions, there may be a special need to encourage
the widest possible use of a certain library, so that it becomes a
de-facto standard. To achieve this, non-free programs must be allowed to
use the library. A more frequent case is that a free library does the
same job as widely used non-free libraries. In this case, there is
little to gain by limiting the free library to free software only, so we
use the Lesser General Public License.

In other cases, permission to use a particular library in non-free
programs enables a greater number of people to use a large body of free
software. For example, permission to use the GNU C Library in non-free
programs enables many more people to use the whole GNU operating system,
as well as its variant, the GNU/Linux operating system.

Although the Lesser General Public License is Less protective of the
users' freedom, it does ensure that the user of a program that is linked
with the Library has the freedom and the wherewithal to run that program
using a modified version of the Library.

The precise terms and conditions for copying, distribution and
modification follow. Pay close attention to the difference between a
"work based on the library" and a "work that uses the library". The
former contains code derived from the library, whereas the latter must
be combined with the library in order to run.

TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

0. This License Agreement applies to any software library or other
program which contains a notice placed by the copyright holder or other
authorized party saying it may be distributed under the terms of this
Lesser General Public License (also called "this License"). Each
licensee is addressed as "you".

A "library" means a collection of software functions and/or data
prepared so as to be conveniently linked with application programs
(which use some of those functions and data) to form executables.

The "Library", below, refers to any such software library or work which
has been distributed under these terms. A "work based on the Library"
means either the Library or any derivative work under copyright law:
that is to say, a work containing the Library or a portion of it, either
verbatim or with modifications and/or translated straightforwardly into
another language. (Hereinafter, translation is included without
limitation in the term "modification".)

"Source code" for a work means the preferred form of the work for making
modifications to it. For a library, complete source code means all the
source code for all modules it contains, plus any associated interface
definition files, plus the scripts used to control compilation and
installation of the library.

Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope. The act of running
a program using the Library is not restricted, and output from such a
program is covered only if its contents constitute a work based on the
Library (independent of the use of the Library in a tool for writing
it). Whether that is true depends on what the Library does and what the
program that uses the Library does.

1. You may copy and distribute verbatim copies of the Library's complete
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the notices
that refer to this License and to the absence of any warranty; and
distribute a copy of this License along with the Library.

You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee.

2. You may modify your copy or copies of the Library or any portion of
it, thus forming a work based on the Library, and copy and distribute
such modifications or work under the terms of Section 1 above, provided
that you also meet all of these conditions:

    a) The modified work must itself be a software library.
    b) You must cause the files modified to carry prominent notices
       stating that you changed the files and the date of any change.
    c) You must cause the whole of the work to be licensed at no
       charge to all third parties under the terms of this License.
    d) If a facility in the modified Library refers to a function or a
       table of data to be supplied by an application program that uses
       the facility, other than as an argument passed when the facility
       is invoked, then you must make a good faith effort to ensure that,
       in the event an application does not supply such function or
       table, the facility still operates, and performs whatever part of
       its purpose remains meaningful.

      (For example, a function in a library to compute square roots has
a purpose that is entirely well-defined independent of the application.
Therefore, Subsection 2d requires that any application-supplied function
or table used by this function must be optional: if the application does
not supply it, the square root function must still compute square
roots.)

      These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the Library, and
can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works. But when you
distribute the same sections as part of a whole which is a work based on
the Library, the distribution of the whole must be on the terms of this
License, whose permissions for other licensees extend to the entire
whole, and thus to each and every part regardless of who wrote it.

      Thus, it is not the intent of this section to claim rights or
contest your rights to work written entirely by you; rather, the intent
is to exercise the right to control the distribution of derivative or
collective works based on the Library.

      In addition, mere aggregation of another work not based on the
Library with the Library (or with a work based on the Library) on a
volume of a storage or distribution medium does not bring the other work
under the scope of this License. 

3. You may opt to apply the terms of the ordinary GNU General Public
License instead of this License to a given copy of the Library. To do
this, you must alter all the notices that refer to this License, so that
they refer to the ordinary GNU General Public License, version 2,
instead of to this License. (If a newer version than version 2 of the
ordinary GNU General Public License has appeared, then you can specify
that version instead if you wish.) Do not make any other change in these
notices.

Once this change is made in a given copy, it is irreversible for that
copy, so the ordinary GNU General Public License applies to all
subsequent copies and derivative works made from that copy.

This option is useful when you wish to copy part of the code of the
Library into a program that is not a library.

4. You may copy and distribute the Library (or a portion or derivative
of it, under Section 2) in object code or executable form under the
terms of Sections 1 and 2 above provided that you accompany it with the
complete corresponding machine-readable source code, which must be
distributed under the terms of Sections 1 and 2 above on a medium
customarily used for software interchange.

If distribution of object code is made by offering access to copy from a
designated place, then offering equivalent access to copy the source
code from the same place satisfies the requirement to distribute the
source code, even though third parties are not compelled to copy the
source along with the object code.

5. A program that contains no derivative of any portion of the Library,
but is designed to work with the Library by being compiled or linked
with it, is called a "work that uses the Library". Such a work, in
isolation, is not a derivative work of the Library, and therefore falls
outside the scope of this License.

However, linking a "work that uses the Library" with the Library creates
an executable that is a derivative of the Library (because it contains
portions of the Library), rather than a "work that uses the library".
The executable is therefore covered by this License. Section 6 states
terms for distribution of such executables.

When a "work that uses the Library" uses material from a header file
that is part of the Library, the object code for the work may be a
derivative work of the Library even though the source code is not.
Whether this is true is especially significant if the work can be linked
without the Library, or if the work is itself a library. The threshold
for this to be true is not precisely defined by law.

If such an object file uses only numerical parameters, data structure
layouts and accessors, and small macros and small inline functions (ten
lines or less in length), then the use of the object file is
unrestricted, regardless of whether it is legally a derivative work.
(Executables containing this object code plus portions of the Library
will still fall under Section 6.)

Otherwise, if the work is a derivative of the Library, you may
distribute the object code for the work under the terms of Section 6.
Any executables containing that work also fall under Section 6, whether
or not they are linked directly with the Library itself.

6. As an exception to the Sections above, you may also combine or link a
"work that uses the Library" with the Library to produce a work
containing portions of the Library, and distribute that work under terms
of your choice, provided that the terms permit modification of the work
for the customer's own use and reverse engineering for debugging such
modifications.

You must give prominent notice with each copy of the work that the
Library is used in it and that the Library and its use are covered by
this License. You must supply a copy of this License. If the work during
execution displays copyright notices, you must include the copyright
notice for the Library among them, as well as a reference directing the
user to the copy of this License. Also, you must do one of these things:

    a) Accompany the work with the complete corresponding
       machine-readable source code for the Library including whatever
       changes were used in the work (which must be distributed under
       Sections 1 and 2 above); and, if the work is an executable linked
       with the Library, with the complete machine-readable "work that
       uses the Library", as object code and/or source code, so that the
       user can modify the Library and then relink to produce a modified
       executable containing the modified Library. (It is understood that
       the user who changes the contents of definitions files in the
       Library will not necessarily be able to recompile the application
       to use the modified definitions.)
    b) Use a suitable shared library mechanism for linking with the
       Library. A suitable mechanism is one that (1) uses at run time a
       copy of the library already present on the user's computer system,
       rather than copying library functions into the executable, and (2)
       will operate properly with a modified version of the library, if
       the user installs one, as long as the modified version is
       interface-compatible with the version that the work was made with.
    c) Accompany the work with a written offer, valid for at least
       three years, to give the same user the materials specified in
       Subsection 6a, above, for a charge no more than the cost of
       performing this distribution.
    d) If distribution of the work is made by offering access to copy
       from a designated place, offer equivalent access to copy the above
       specified materials from the same place.
    e) Verify that the user has already received a copy of these
       materials or that you have already sent this user a copy. 

For an executable, the required form of the "work that uses the Library"
must include any data and utility programs needed for reproducing the
executable from it. However, as a special exception, the materials to be
distributed need not include anything that is normally distributed (in
either source or binary form) with the major components (compiler,
kernel, and so on) of the operating system on which the executable runs,
unless that component itself accompanies the executable.

It may happen that this requirement contradicts the license restrictions
of other proprietary libraries that do not normally accompany the
operating system. Such a contradiction means you cannot use both them
and the Library together in an executable that you distribute.

7. You may place library facilities that are a work based on the Library
side-by-side in a single library together with other library facilities
not covered by this License, and distribute such a combined library,
provided that the separate distribution of the work based on the Library
and of the other library facilities is otherwise permitted, and provided
that you do these two things:

    a) Accompany the combined library with a copy of the same work
       based on the Library, uncombined with any other library
       facilities. This must be distributed under the terms of the
       Sections above.
    b) Give prominent notice with the combined library of the fact
       that part of it is a work based on the Library, and explaining
       where to find the accompanying uncombined form of the same work. 

8. You may not copy, modify, sublicense, link with, or distribute the
Library except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense, link with, or distribute the
Library 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.

9. You are not required to accept this License, since you have not
signed it. However, nothing else grants you permission to modify or
distribute the Library or its derivative works. These actions are
prohibited by law if you do not accept this License. Therefore, by
modifying or distributing the Library (or any work based on the
Library), you indicate your acceptance of this License to do so, and all
its terms and conditions for copying, distributing or modifying the
Library or works based on it.

10. Each time you redistribute the Library (or any work based on the
Library), the recipient automatically receives a license from the
original licensor to copy, distribute, link with or modify the Library
subject to these terms and conditions. You may not impose any further
restrictions on the recipients' exercise of the rights granted herein.
You are not responsible for enforcing compliance by third parties with
this License.

11. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent issues),
conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License. If you cannot distribute
so as to satisfy simultaneously your obligations under this License and
any other pertinent obligations, then as a consequence you may not
distribute the Library at all. For example, if a patent license would
not permit royalty-free redistribution of the Library by all those who
receive copies directly or indirectly through you, then the only way you
could satisfy both it and this License would be to refrain entirely from
distribution of the Library.

If any portion of this section is held invalid or unenforceable under
any particular circumstance, the balance of the section is intended to
apply, and the section as a whole is intended to apply in other
circumstances.

It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of any
such claims; this section has the sole purpose of protecting the
integrity of the free software distribution system which is implemented
by public license practices. Many people have made generous
contributions to the wide range of software distributed through that
system in reliance on consistent application of that system; it is up to
the author/donor to decide if he or she is willing to distribute
software through any other system and a licensee cannot impose that
choice.

This section is intended to make thoroughly clear what is believed to be
a consequence of the rest of this License.

12. If the distribution and/or use of the Library is restricted in
certain countries either by patents or by copyrighted interfaces, the
original copyright holder who places the Library under this License may
add an explicit geographical distribution limitation excluding those
countries, so that distribution is permitted only in or among countries
not thus excluded. In such case, this License incorporates the
limitation as if written in the body of this License.

13. The Free Software Foundation may publish revised and/or new versions
of the Lesser General Public 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.

Each version is given a distinguishing version number. If the Library
specifies a version number of this License which applies to it and "any
later version", you have the option of following the terms and
conditions either of that version or of any later version published by
the Free Software Foundation. If the Library does not specify a license
version number, you may choose any version ever published by the Free
Software Foundation.

14. If you wish to incorporate parts of the Library into other free
programs whose distribution conditions are incompatible with these,
write to the author to ask for permission. For software which is
copyrighted by the Free Software Foundation, write to the Free Software
Foundation; we sometimes make exceptions for this. Our decision will be
guided by the two goals of preserving the free status of all derivatives
of our free software and of promoting the sharing and reuse of software
generally.

NO WARRANTY

15. BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE LIBRARY "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE LIBRARY IS WITH
YOU. SHOULD THE LIBRARY PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
NECESSARY SERVICING, REPAIR OR CORRECTION.

16. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY
AND/OR REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE LIABLE TO YOU FOR
DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL
DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE LIBRARY
(INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED
INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF
THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR
OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.