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[GNU GENERAL PUBLIC LICENSE]
Version 2, June 1991
Copyright © 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 othe r 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.

GNU GENERAL PUBLIC LICENSE

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 prom inent 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 progr am 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,