license

GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007

Copyright © 2007 Free Software Foundation, Inc. <https://fsf.org/>

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

Preamble The GNU General Public License is a free, copyleft license
for software and other kinds of works.

The licenses for most software and other practical works are designed
to take away your freedom to share and change the works. By contrast,
the GNU General Public License is intended to guarantee your freedom
to share and change all versions of a program--to make sure it remains
free software for all its users. We, the Free Software Foundation, use
the GNU General Public License for most of our software; it applies
also to any other work released this way by its authors. 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
them 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 prevent others from denying you
these rights or asking you to surrender the rights. Therefore, you
have certain responsibilities if you distribute copies of the
software, or if you modify it: responsibilities to respect the freedom
of others.

For example, if you distribute copies of such a program, whether
gratis or for a fee, you must pass on to the recipients the same
freedoms that you received. 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.

Developers that use the GNU GPL protect your rights with two steps:
(1) assert copyright on the software, and (2) offer you this License
giving you legal permission to copy, distribute and/or modify it.

For the developers' and authors' protection, the GPL clearly explains
that there is no warranty for this free software. For both users' and
authors' sake, the GPL requires that modified versions be marked as
changed, so that their problems will not be attributed erroneously to
authors of previous versions.

Some devices are designed to deny users access to install or run
modified versions of the software inside them, although the
manufacturer can do so. This is fundamentally incompatible with the
aim of protecting users' freedom to change the software. The
systematic pattern of such abuse occurs in the area of products for
individuals to use, which is precisely where it is most
unacceptable. Therefore, we have designed this version of the GPL to
prohibit the practice for those products. If such problems arise
substantially in other domains, we stand ready to extend this
provision to those domains in future versions of the GPL, as needed to
protect the freedom of users.

Finally, every program is threatened constantly by software
patents. States should not allow patents to restrict development and
use of software on general-purpose computers, but in those that do, we
wish to avoid the special danger that patents applied to a free
program could make it effectively proprietary. To prevent this, the
GPL assures that patents cannot be used to render the program
non-free.

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

TERMS AND CONDITIONS 0. Definitions.  “This License” refers to version
3 of the GNU General Public License.

“Copyright” also means copyright-like laws that apply to other kinds
of works, such as semiconductor masks.

“The Program” refers to any copyrightable work licensed under this
License. Each licensee is addressed as “you”. “Licensees” and
“recipients” may be individuals or organizations.

To “modify” a work means to copy from or adapt all or part of the work
in a fashion requiring copyright permission, other than the making of
an exact copy. The resulting work is called a “modified version” of
the earlier work or a work “based on” the earlier work.

A “covered work” means either the unmodified Program or a work based
on the Program.

To “propagate” a work means to do anything with it that, without
permission, would make you directly or secondarily liable for
infringement under applicable copyright law, except executing it on a
computer or modifying a private copy. Propagation includes copying,
distribution (with or without modification), making available to the
public, and in some countries other activities as well.

To “convey” a work means any kind of propagation that enables other
parties to make or receive copies. Mere interaction with a user
through a computer network, with no transfer of a copy, is not
conveying.

An interactive user interface displays “Appropriate Legal Notices” to
the extent that it includes a convenient and prominently visible
feature that (1) displays an appropriate copyright notice, and (2)
tells the user that there is no warranty for the work (except to the
extent that warranties are provided), that licensees may convey the
work under this License, and how to view a copy of this License. If
the interface presents a list of user commands or options, such as a
menu, a prominent item in the list meets this criterion.

1. Source Code.  The “source code” for a work means the preferred form
of the work for making modifications to it. “Object code” means any
non-source form of a work.

A “Standard Interface” means an interface that either is an official
standard defined by a recognized standards body, or, in the case of
interfaces specified for a particular programming language, one that
is widely used among developers working in that language.

The “System Libraries” of an executable work include anything, other
than the work as a whole, that (a) is included in the normal form of
packaging a Major Component, but which is not part of that Major
Component, and (b) serves only to enable use of the work with that
Major Component, or to implement a Standard Interface for which an
implementation is available to the public in source code form. A
“Major Component”, in this context, means a major essential component
(kernel, window system, and so on) of the specific operating system
(if any) on which the executable work runs, or a compiler used to
produce the work, or an object code interpreter used to run it.

The “Corresponding Source” for a work in object code form means all
the source code needed to generate, install, and (for an executable
work) run the object code and to modify the work, including scripts to
control those activities. However, it does not include the work's
System Libraries, or general-purpose tools or generally available free
programs which are used unmodified in performing those activities but
which are not part of the work. For example, Corresponding Source
includes interface definition files associated with source files for
the work, and the source code for shared libraries and dynamically
linked subprograms that the work is specifically designed to require,
such as by intimate data communication or control flow between those
subprograms and other parts of the work.

The Corresponding Source need not include anything that users can
regenerate automatically from other parts of the Corresponding Source.

The Corresponding Source for a work in source code form is that same
work.

2. Basic Permissions.  All rights granted under this License are
granted for the term of copyright on the Program, and are irrevocable
provided the stated conditions are met. This License explicitly
affirms your unlimited permission to run the unmodified Program. The
output from running a covered work is covered by this License only if
the output, given its content, constitutes a covered work. This
License acknowledges your rights of fair use or other equivalent, as
provided by copyright law.

You may make, run and propagate covered works that you do not convey,
without conditions so long as your license otherwise remains in
force. You may convey covered works to others for the sole purpose of
having them make modifications exclusively for you, or provide you
with facilities for running those works, provided that you comply with
the terms of this License in conveying all material for which you do
not control copyright. Those thus making or running the covered works
for you must do so exclusively on your behalf, under your direction
and control, on terms that prohibit them from making any copies of
your copyrighted material outside their relationship with you.

Conveying under any other circumstances is permitted solely under the
conditions stated below. Sublicensing is not allowed; section 10 makes
it unnecessary.

3. Protecting Users' Legal Rights From Anti-Circumvention Law.  No
covered work shall be deemed part of an effective technological
measure under any applicable law fulfilling obligations under article
11 of the WIPO copyright treaty adopted on 20 December 1996, or
similar laws prohibiting or restricting circumvention of such
measures.

When you convey a covered work, you waive any legal power to forbid
circumvention of technological measures to the extent such
circumvention is effected by exercising rights under this License with
respect to the covered work, and you disclaim any intention to limit
operation or modification of the work as a means of enforcing, against
the work's users, your or third parties' legal rights to forbid
circumvention of technological measures.

4. Conveying Verbatim Copies.  You may convey 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; keep intact all notices stating that
this License and any non-permissive terms added in accord with section
7 apply to the code; keep intact all notices of the absence of any
warranty; and give all recipients a copy of this License along with
the Program.

You may charge any price or no price for each copy that you convey,
and you may offer support or warranty protection for a fee.

5. Conveying Modified Source Versions.  You may convey a work based on
the Program, or the modifications to produce it from the Program, in
the form of source code under the terms of section 4, provided that
you also meet all of these conditions:

a) The work must carry prominent notices stating that you modified it,
and giving a relevant date.  b) The work must carry prominent notices
stating that it is released under this License and any conditions
added under section 7. This requirement modifies the requirement in
section 4 to “keep intact all notices”.  c) You must license the
entire work, as a whole, under this License to anyone who comes into
possession of a copy. This License will therefore apply, along with
any applicable section 7 additional terms, to the whole of the work,
and all its parts, regardless of how they are packaged. This License
gives no permission to license the work in any other way, but it does
not invalidate such permission if you have separately received it.  d)
If the work has interactive user interfaces, each must display
Appropriate Legal Notices; however, if the Program has interactive
interfaces that do not display Appropriate Legal Notices, your work
need not make them do so.  A compilation of a covered work with other
separate and independent works, which are not by their nature
extensions of the covered work, and which are not combined with it
such as to form a larger program, in or on a volume of a storage or
distribution medium, is called an “aggregate” if the compilation and
its resulting copyright are not used to limit the access or legal
rights of the compilation's users beyond what the individual works
permit. Inclusion of a covered work in an aggregate does not cause
this License to apply to the other parts of the aggregate.

6. Conveying Non-Source Forms.  You may convey a covered work in
object code form under the terms of sections 4 and 5, provided that
you also convey the machine-readable Corresponding Source under the
terms of this License, in one of these ways:

a) Convey the object code in, or embodied in, a physical product
(including a physical distribution medium), accompanied by the
Corresponding Source fixed on a durable physical medium customarily
used for software interchange.  b) Convey the object code in, or
embodied in, a physical product (including a physical distribution
medium), accompanied by a written offer, valid for at least three
years and valid for as long as you offer spare parts or customer
support for that product model, to give anyone who possesses the
object code either (1) a copy of the Corresponding Source for all the
software in the product that is covered by this License, on a durable
physical medium customarily used for software interchange, for a price
no more than your reasonable cost of physically performing this
conveying of source, or (2) access to copy the Corresponding Source
from a network server at no charge.  c) Convey individual copies of
the object code with a copy of the written offer to provide the
Corresponding Source. This alternative is allowed only occasionally
and noncommercially, and only if you received the object code with
such an offer, in accord with subsection 6b.  d) Convey the object
code by offering access from a designated place (gratis or for a
charge), and offer equivalent access to the Corresponding Source in
the same way through the same place at no further charge. You need not
require recipients to copy the Corresponding Source along with the
object code. If the place to copy the object code is a network server,
the Corresponding Source may be on a different server (operated by you
or a third party) that supports equivalent copying facilities,
provided you maintain clear directions next to the object code saying
where to find the Corresponding Source. Regardless of what server
hosts the Corresponding Source, you remain obligated to ensure that it
is available for as long as needed to satisfy these requirements.  e)
Convey the object code using peer-to-peer transmission, provided you
inform other peers where the object code and Corresponding Source of
the work are being offered to the general public at no charge under
subsection 6d.  A separable portion of the object code, whose source
code is excluded from the Corresponding Source as a System Library,
need not be included in conveying the object code work.

A “User Product” is either (1) a “consumer product”, which means any
tangible personal property which is normally used for personal,
family, or household purposes, or (2) anything designed or sold for
incorporation into a dwelling. In determining whether a product is a
consumer product, doubtful cases shall be resolved in favor of
coverage. For a particular product received by a particular user,
“normally used” refers to a typical or common use of that class of
product, regardless of the status of the particular user or of the way
in which the particular user actually uses, or expects or is expected
to use, the product. A product is a consumer product regardless of
whether the product has substantial commercial, industrial or
non-consumer uses, unless such uses represent the only significant
mode of use of the product.

“Installation Information” for a User Product means any methods,
procedures, authorization keys, or other information required to
install and execute modified versions of a covered work in that User
Product from a modified version of its Corresponding Source. The
information must suffice to ensure that the continued functioning of
the modified object code is in no case prevented or interfered with
solely because modification has been made.

If you convey an object code work under this section in, or with, or
specifically for use in, a User Product, and the conveying occurs as
part of a transaction in which the right of possession and use of the
User Product is transferred to the recipient in perpetuity or for a
fixed term (regardless of how the transaction is characterized), the
Corresponding Source conveyed under this section must be accompanied
by the Installation Information. But this requirement does not apply
if neither you nor any third party retains the ability to install
modified object code on the User Product (for example, the work has
been installed in ROM).

The requirement to provide Installation Information does not include a
requirement to continue to provide support service, warranty, or
updates for a work that has been modified or installed by the
recipient, or for the User Product in which it has been modified or
installed. Access to a network may be denied when the modification
itself materially and adversely affects the operation of the network
or violates the rules and protocols for communication across the
network.

Corresponding Source conveyed, and Installation Information provided,
in accord with this section must be in a format that is publicly
documented (and with an implementation available to the public in
source code form), and must require no special password or key for
unpacking, reading or copying.

7. Additional Terms.  “Additional permissions” are terms that
supplement the terms of this License by making exceptions from one or
more of its conditions. Additional permissions that are applicable to
the entire Program shall be treated as though they were included in
this License, to the extent that they are valid under applicable
law. If additional permissions apply only to part of the Program, that
part may be used separately under those permissions, but the entire
Program remains governed by this License without regard to the
additional permissions.

When you convey a copy of a covered work, you may at your option
remove any additional permissions from that copy, or from any part of
it. (Additional permissions may be written to require their own
removal in certain cases when you modify the work.) You may place
additional permissions on material, added by you to a covered work,
for which you have or can give appropriate copyright permission.

Notwithstanding any other provision of this License, for material you
add to a covered work, you may (if authorized by the copyright holders
of that material) supplement the terms of this License with terms:

a) Disclaiming warranty or limiting liability differently from the
terms of sections 15 and 16 of this License; or b) Requiring
preservation of specified reasonable legal notices or author
attributions in that material or in the Appropriate Legal Notices
displayed by works containing it; or c) Prohibiting misrepresentation
of the origin of that material, or requiring that modified versions of
such material be marked in reasonable ways as different from the
original version; or d) Limiting the use for publicity purposes of
names of licensors or authors of the material; or e) Declining to
grant rights under trademark law for use of some trade names,
trademarks, or service marks; or f) Requiring indemnification of
licensors and authors of that material by anyone who conveys the
material (or modified versions of it) with contractual assumptions of
liability to the recipient, for any liability that these contractual
assumptions directly impose on those licensors and authors.  All other
non-permissive additional terms are considered “further restrictions”
within the meaning of section 10. If the Program as you received it,
or any part of it, contains a notice stating that it is governed by
this License along with a term that is a further restriction, you may
remove that term. If a license document contains a further restriction
but permits relicensing or conveying under this License, you may add
to a covered work material governed by the terms of that license
document, provided that the further restriction does not survive such
relicensing or conveying.

If you add terms to a covered work in accord with this section, you
must place, in the relevant source files, a statement of the
additional terms that apply to those files, or a notice indicating
where to find the applicable terms.

Additional terms, permissive or non-permissive, may be stated in the
form of a separately written license, or stated as exceptions; the
above requirements apply either way.

8. Termination.  You may not propagate or modify a covered work except
as expressly provided under this License. Any attempt otherwise to
propagate or modify it is void, and will automatically terminate your
rights under this License (including any patent licenses granted under
the third paragraph of section 11).

However, if you cease all violation of this License, then your license
from a particular copyright holder is reinstated (a) provisionally,
unless and until the copyright holder explicitly and finally
terminates your license, and (b) permanently, if the copyright holder
fails to notify you of the violation by some reasonable means prior to
60 days after the cessation.

Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from that
copyright holder, and you cure the violation prior to 30 days after
your receipt of the notice.

Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under
this License. If your rights have been terminated and not permanently
reinstated, you do not qualify to receive new licenses for the same
material under section 10.

9. Acceptance Not Required for Having Copies.  You are not required to
accept this License in order to receive or run a copy of the
Program. Ancillary propagation of a covered work occurring solely as a
consequence of using peer-to-peer transmission to receive a copy
likewise does not require acceptance. However, nothing other than this
License grants you permission to propagate or modify any covered
work. These actions infringe copyright if you do not accept this
License. Therefore, by modifying or propagating a covered work, you
indicate your acceptance of this License to do so.

10. Automatic Licensing of Downstream Recipients.  Each time you
convey a covered work, the recipient automatically receives a license
from the original licensors, to run, modify and propagate that work,
subject to this License. You are not responsible for enforcing
compliance by third parties with this License.

An “entity transaction” is a transaction transferring control of an
organization, or substantially all assets of one, or subdividing an
organization, or merging organizations. If propagation of a covered
work results from an entity transaction, each party to that
transaction who receives a copy of the work also receives whatever
licenses to the work the party's predecessor in interest had or could
give under the previous paragraph, plus a right to possession of the
Corresponding Source of the work from the predecessor in interest, if
the predecessor has it or can get it with reasonable efforts.

You may not impose any further restrictions on the exercise of the
rights granted or affirmed under this License. For example, you may
not impose a license fee, royalty, or other charge for exercise of
rights granted under this License, and you may not initiate litigation
(including a cross-claim or counterclaim in a lawsuit) alleging that
any patent claim is infringed by making, using, selling, offering for
sale, or importing the Program or any portion of it.

11. Patents.  A “contributor” is a copyright holder who authorizes use
under this License of the Program or a work on which the Program is
based. The work thus licensed is called the contributor's “contributor
version”.

A contributor's “essential patent claims” are all patent claims owned
or controlled by the contributor, whether already acquired or
hereafter acquired, that would be infringed by some manner, permitted
by this License, of making, using, or selling its contributor version,
but do not include claims that would be infringed only as a
consequence of further modification of the contributor version. For
purposes of this definition, “control” includes the right to grant
patent sublicenses in a manner consistent with the requirements of
this License.

Each contributor grants you a non-exclusive, worldwide, royalty-free
patent license under the contributor's essential patent claims, to
make, use, sell, offer for sale, import and otherwise run, modify and
propagate the contents of its contributor version.

In the following three paragraphs, a “patent license” is any express
agreement or commitment, however denominated, not to enforce a patent
(such as an express permission to practice a patent or covenant not to
sue for patent infringement). To “grant” such a patent license to a
party means to make such an agreement or commitment not to enforce a
patent against the party.

If you convey a covered work, knowingly relying on a patent license,
and the Corresponding Source of the work is not available for anyone
to copy, free of charge and under the terms of this License, through a
publicly available network server or other readily accessible means,
then you must either (1) cause the Corresponding Source to be so
available, or (2) arrange to deprive yourself of the benefit of the
patent license for this particular work, or (3) arrange, in a manner
consistent with the requirements of this License, to extend the patent
license to downstream recipients. “Knowingly relying” means you have
actual knowledge that, but for the patent license, your conveying the
covered work in a country, or your recipient's use of the covered work
in a country, would infringe one or more identifiable patents in that
country that you have reason to believe are valid.

If, pursuant to or in connection with a single transaction or
arrangement, you convey, or propagate by procuring conveyance of, a
covered work, and grant a patent license to some of the parties
receiving the covered work authorizing them to use, propagate, modify
or convey a specific copy of the covered work, then the patent license
you grant is automatically extended to all recipients of the covered
work and works based on it.

A patent license is “discriminatory” if it does not include within the
scope of its coverage, prohibits the exercise of, or is conditioned on
the non-exercise of one or more of the rights that are specifically
granted under this License. You may not convey a covered work if you
are a party to an arrangement with a third party that is in the
business of distributing software, under which you make payment to the
third party based on the extent of your activity of conveying the
work, and under which the third party grants, to any of the parties
who would receive the covered work from you, a discriminatory patent
license (a) in connection with copies of the covered work conveyed by
you (or copies made from those copies), or (b) primarily for and in
connection with specific products or compilations that contain the
covered work, unless you entered into that arrangement, or that patent
license was granted, prior to 28 March 2007.

Nothing in this License shall be construed as excluding or limiting
any implied license or other defenses to infringement that may
otherwise be available to you under applicable patent law.

12. No Surrender of Others' Freedom.  If 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 convey a covered work so as to satisfy
simultaneously your obligations under this License and any other
pertinent obligations, then as a consequence you may not convey it at
all. For example, if you agree to terms that obligate you to collect a
royalty for further conveying from those to whom you convey the
Program, the only way you could satisfy both those terms and this
License would be to refrain entirely from conveying the Program.

13. Use with the GNU Affero General Public License.  Notwithstanding
any other provision of this License, you have permission to link or
combine any covered work with a work licensed under version 3 of the
GNU Affero General Public License into a single combined work, and to
convey the resulting work. The terms of this License will continue to
apply to the part which is the covered work, but the special
requirements of the GNU Affero General Public License, section 13,
concerning interaction through a network will apply to the combination
as such.

14. Revised Versions of this License.  The Free Software Foundation
may publish revised and/or new versions of the GNU 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 that a certain numbered version of the GNU General Public
License “or any later version” applies to it, you have the option of
following the terms and conditions either of that numbered version or
of any later version published by the Free Software Foundation. If the
Program does not specify a version number of the GNU General Public
License, you may choose any version ever published by the Free
Software Foundation.

If the Program specifies that a proxy can decide which future versions
of the GNU General Public License can be used, that proxy's public
statement of acceptance of a version permanently authorizes you to
choose that version for the Program.

Later license versions may give you additional or different
permissions. However, no additional obligations are imposed on any
author or copyright holder as a result of your choosing to follow a
later version.

15. Disclaimer of Warranty.  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.

16. Limitation of Liability.  IN NO EVENT UNLESS REQUIRED BY
APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR
ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS 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.

17. Interpretation of Sections 15 and 16.  If the disclaimer of
warranty and limitation of liability provided above cannot be given
local legal effect according to their terms, reviewing courts shall
apply local law that most closely approximates an absolute waiver of
all civil liability in connection with the Program, unless a warranty
or assumption of liability accompanies a copy of the Program in return
for a fee.

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 state
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 a brief idea of what it
    does.> Copyright (C) <year> <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 3 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, see
    <https://www.gnu.org/licenses/>.  Also add information on how to
    contact you by electronic and paper mail.

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

    <program> Copyright (C) <year> <name of author> This program 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, your program's commands
    might be different; for a GUI interface, you would use an “about
    box”.

You should also get your employer (if you work as a programmer) or
school, if any, to sign a “copyright disclaimer” for the program, if
necessary. For more information on this, and how to apply and follow
the GNU GPL, see <https://www.gnu.org/licenses/>.

The GNU 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. But first,
please read <https://www.gnu.org/licenses/why-not-lgpl.html>.