GPL-2.0-or-later

GNU GENERAL PUBLIC LICENSE

Version 2, June 1991

Copyright (C) 1989, 1991 Free Software Foundation, Inc.

51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 , USA

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.

Preamble

The licenses for most software are designed to take away your freedom
to share and change it. By contrast, the GNU General Public License is
intended to guarantee your freedom to share and change free software--to
make sure the software is free for all its users. This General Public
License applies to most of the Free Software Foundation's software and
to any other program whose authors commit to using it. (Some other Free
Software Foundation software is covered by the GNU Lesser General Public
License instead.) You can apply it to your programs, too.

When we speak of free software, we are referring to freedom, 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 or use pieces of it in
new free programs; and that you know you can do these things.

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

For example, if you distribute copies of such a program, whether gratis or
for a fee, you must give the recipients all the rights that you have. You
must make sure that they, too, receive or can get the source code. And
you must show them these terms so they know their rights.

We protect your rights with two steps: (1) copyright the software, and
(2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.

Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
software. If the software is modified by someone else and passed on,
we want its recipients to know that what they have is not the original,
so that any problems introduced by others will not reflect on the original
authors' reputations.

Finally, any free program is threatened constantly by software
patents. We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making the
program proprietary. To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.

The precise terms and conditions for copying, distribution and
modification follow.

TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

   0. This License applies to any program or other work which contains
   a notice placed by the copyright holder saying it may be distributed
   under the terms of this General Public License. The "Program", below,
   refers to any such program or work, and a "work based on the Program"
   means either the Program or any derivative work under copyright law:
   that is to say, a work containing the Program or a portion of it,
   either verbatim or with modifications and/or translated into another
   language. (Hereinafter, translation is included without limitation
   in the term "modification".) Each licensee is addressed as "you".

   Activities other than copying, distribution and modification are not
   covered by this License; they are outside its scope. The act of running
   the Program is not restricted, and the output from the Program is
   covered only if its contents constitute a work based on the Program
   (independent of having been made by running the Program). Whether
   that is true depends on what the Program does.

   1. You may copy and distribute verbatim copies of the Program's 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 give any
   other recipients of the Program a copy of this License along with
   the Program.

   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 Program or any portion of
   it, thus forming a work based on the Program, 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) You must cause the modified files to carry prominent notices
      stating that you changed the files and the date of any change.

      b) You must cause any work that you distribute or publish, that
      in whole or in part contains or is derived from the Program or
      any part thereof, to be licensed as a whole at no charge to all
      third parties under the terms of this License.

      c) If the modified program normally reads commands interactively
      when run, you must cause it, when started running for such
      interactive use in the most ordinary way, to print or display
      an announcement including an appropriate copyright notice and
      a notice that there is no warranty (or else, saying that you
      provide a warranty) and that users may redistribute the program
      under these conditions, and telling the user how to view a copy
      of this License. (Exception: if the Program itself is interactive
      but does not normally print such an announcement, your work based
      on the Program is not required to print an announcement.)

   These requirements apply to the modified work as a whole. If
   identifiable sections of that work are not derived from the Program,
   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 Program, 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 Program.

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

   3. You may copy and distribute the Program (or a work based on it,
   under Section 2) in object code or executable form under the terms of
   Sections 1 and 2 above provided that you also do one of the following:

      a) 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;
      or,

      b) Accompany it with a written offer, valid for at least three
      years, to give any third party, for a charge no more than your
      cost of physically performing source distribution, a complete
      machine-readable copy of the corresponding source code, to be
      distributed under the terms of Sections 1 and 2 above on a medium
      customarily used for software interchange; or,

      c) Accompany it with the information you received as to the offer to
      distribute corresponding source code. (This alternative is allowed
      only for noncommercial distribution and only if you received the
      program in object code or executable form with such an offer,
      in accord with Subsection b above.)

   The source code for a work means the preferred form of the work
   for making modifications to it. For an executable work, 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 executable. However,
   as a special exception, the source code 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.

   If distribution of executable or 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 counts as distribution of
   the source code, even though third parties are not compelled to copy
   the source along with the object code.

   4. You may not copy, modify, sublicense, or distribute the Program
   except as expressly provided under this License. Any attempt otherwise
   to copy, modify, sublicense or distribute the Program 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.

   5. 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 Program or its derivative works. These actions
   are prohibited by law if you do not accept this License. Therefore,
   by modifying or distributing the Program (or any work based on the
   Program), you indicate your acceptance of this License to do so, and
   all its terms and conditions for copying, distributing or modifying
   the Program or works based on it.

   6. Each time you redistribute the Program (or any work based on the
   Program), the recipient automatically receives a license from the
   original licensor to copy, distribute or modify the Program 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 to this License.

   7. 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 Program at all. For example, if a patent
   license would not permit royalty-free redistribution of the Program
   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 Program.

   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.

   8. If the distribution and/or use of the Program is restricted in
   certain countries either by patents or by copyrighted interfaces, the
   original copyright holder who places the Program 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.

   9. The Free Software Foundation may publish revised and/or new versions
   of the 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 Program
   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 Program does not specify
   a version number of this License, you may choose any version ever
   published by the Free Software Foundation.

   10. If you wish to incorporate parts of the Program into other free
   programs whose distribution conditions are different, 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

   11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO
   WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE
   LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS
   AND/OR OTHER PARTIES PROVIDE THE PROGRAM "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
   PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
   THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

   12. 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 PROGRAM 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 PROGRAM (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 PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN
   IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
   SUCH DAMAGES. END OF TERMS AND CONDITIONS

How to Apply These Terms to Your New Programs

If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these
terms.

To do so, attach the following notices to the program. It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least the
"copyright" line and a pointer to where the full notice is found.

<one line to give the program's name and an idea of what it does.>

Copyright (C) <yyyy> <name of author>

This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2 of the License, or (at your
option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 , USA.

Also add information on how to contact you by electronic and paper mail.

If the program is interactive, make it output a short notice like this
when it starts in an interactive mode:

Gnomovision version 69, Copyright (C) year name of author Gnomovision
comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is
free software, and you are welcome to redistribute it under certain
conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the
appropriate parts of the General Public License. Of course, the commands
you use may be called something other than `show w' and `show c'; they
could even be mouse-clicks or menu items--whatever suits your program.

You should also get your employer (if you work as a programmer) or
your school, if any, to sign a "copyright disclaimer" for the program,
if necessary. Here is a sample; alter the names:

Yoyodyne, Inc., hereby disclaims all copyright interest in the program
`Gnomovision' (which makes passes at compilers) written by James Hacker.

< signature of Ty Coon > , 1 April 1989 Ty Coon, President of Vice This
General Public License does not permit incorporating your program into
proprietary programs. If your program is a subroutine library, you may
consider it more useful to permit linking proprietary applications with
the library. If this is what you want to do, use the GNU Lesser General
Public License instead of this License.