license: URL: https://github.com/coq-community/fourcolor.git
  CeCILL-B FREE SOFTWARE LICENSE AGREEMENT
  
  
      Notice
  
  This Agreement is a Free Software license agreement that is the result
  of discussions between its authors in order to ensure compliance with
  the two main principles guiding its drafting:
  
      * firstly, compliance with the principles governing the distribution
        of Free Software: access to source code, broad rights granted to
        users,
      * secondly, the election of a governing law, French law, with which
        it is conformant, both as regards the law of torts and
        intellectual property law, and the protection that it offers to
        both authors and holders of the economic rights over software.
  
  The authors of the CeCILL-B (for Ce[a] C[nrs] I[nria] L[ogiciel] L[ibre])
  license are: 
  
  Commissariat \xe0 l'Energie Atomique - CEA, a public scientific, technical
  and industrial research establishment, having its principal place of
  business at 25 rue Leblanc, immeuble Le Ponant D, 75015 Paris, France.
  
  Centre National de la Recherche Scientifique - CNRS, a public scientific
  and technological establishment, having its principal place of business
  at 3 rue Michel-Ange, 75794 Paris cedex 16, France.
  
  Institut National de Recherche en Informatique et en Automatique -
  INRIA, a public scientific and technological establishment, having its
  principal place of business at Domaine de Voluceau, Rocquencourt, BP
  105, 78153 Le Chesnay cedex, France.
  
  
      Preamble
  
  This Agreement is an open source software license intended to give users
  significant freedom to modify and redistribute the software licensed
  hereunder.
  
  The exercising of this freedom is conditional upon a strong obligation
  of giving credits for everybody that distributes a software
  incorporating a software ruled by the current license so as all
  contributions to be properly identified and acknowledged.
  
  In consideration of access to the source code and the rights to copy,
  modify and redistribute granted by the license, users are provided only
  with a limited warranty and the software's author, the holder of the
  economic rights, and the successive licensors only have limited liability.
  
  In this respect, the risks associated with loading, using, modifying
  and/or developing or reproducing the software by the user are brought to
  the user's attention, given its Free Software status, which may make it
  complicated to use, with the result that its use is reserved for
  developers and experienced professionals having in-depth computer
  knowledge. Users are therefore encouraged to load and test the
  suitability of the software as regards their requirements in conditions
  enabling the security of their systems and/or data to be ensured and,
  more generally, to use and operate it in the same conditions of
  security. This Agreement may be freely reproduced and published,
  provided it is not altered, and that no provisions are either added or
  removed herefrom.
  
  This Agreement may apply to any or all software for which the holder of
  the economic rights decides to submit the use thereof to its provisions.
  
  
      Article 1 - DEFINITIONS
  
  For the purpose of this Agreement, when the following expressions
  commence with a capital letter, they shall have the following meaning:
  
  Agreement: means this license agreement, and its possible subsequent
  versions and annexes.
  
  Software: means the software in its Object Code and/or Source Code form
  and, where applicable, its documentation, "as is" when the Licensee
  accepts the Agreement.
  
  Initial Software: means the Software in its Source Code and possibly its
  Object Code form and, where applicable, its documentation, "as is" when
  it is first distributed under the terms and conditions of the Agreement.
  
  Modified Software: means the Software modified by at least one
  Contribution.
  
  Source Code: means all the Software's instructions and program lines to
  which access is required so as to modify the Software.
  
  Object Code: means the binary files originating from the compilation of
  the Source Code.
  
  Holder: means the holder(s) of the economic rights over the Initial
  Software.
  
  Licensee: means the Software user(s) having accepted the Agreement.
  
  Contributor: means a Licensee having made at least one Contribution.
  
  Licensor: means the Holder, or any other individual or legal entity, who
  distributes the Software under the Agreement.
  
  Contribution: means any or all modifications, corrections, translations,
  adaptations and/or new functions integrated into the Software by any or
  all Contributors, as well as any or all Internal Modules.
  
  Module: means a set of sources files including their documentation that
  enables supplementary functions or services in addition to those offered
  by the Software.
  
  External Module: means any or all Modules, not derived from the
  Software, so that this Module and the Software run in separate address
  spaces, with one calling the other when they are run.
  
  Internal Module: means any or all Module, connected to the Software so
  that they both execute in the same address space.
  
  Parties: mean both the Licensee and the Licensor.
  
  These expressions may be used both in singular and plural form.
  
  
      Article 2 - PURPOSE
  
  The purpose of the Agreement is the grant by the Licensor to the
  Licensee of a non-exclusive, transferable and worldwide license for the
  Software as set forth in Article 5 hereinafter for the whole term of the
  protection granted by the rights over said Software.
  
  
      Article 3 - ACCEPTANCE
  
  3.1 The Licensee shall be deemed as having accepted the terms and
  conditions of this Agreement upon the occurrence of the first of the
  following events:
  
      * (i) loading the Software by any or all means, notably, by
        downloading from a remote server, or by loading from a physical
        medium;
      * (ii) the first time the Licensee exercises any of the rights
        granted hereunder.
  
  3.2 One copy of the Agreement, containing a notice relating to the
  characteristics of the Software, to the limited warranty, and to the
  fact that its use is restricted to experienced users has been provided
  to the Licensee prior to its acceptance as set forth in Article 3.1
  hereinabove, and the Licensee hereby acknowledges that it has read and
  understood it.
  
  
      Article 4 - EFFECTIVE DATE AND TERM
  
  
        4.1 EFFECTIVE DATE
  
  The Agreement shall become effective on the date when it is accepted by
  the Licensee as set forth in Article 3.1.
  
  
        4.2 TERM
  
  The Agreement shall remain in force for the entire legal term of
  protection of the economic rights over the Software.
  
  
      Article 5 - SCOPE OF RIGHTS GRANTED
  
  The Licensor hereby grants to the Licensee, who accepts, the following
  rights over the Software for any or all use, and for the term of the
  Agreement, on the basis of the terms and conditions set forth hereinafter.
  
  Besides, if the Licensor owns or comes to own one or more patents
  protecting all or part of the functions of the Software or of its
  components, the Licensor undertakes not to enforce the rights granted by
  these patents against successive Licensees using, exploiting or
  modifying the Software. If these patents are transferred, the Licensor
  undertakes to have the transferees subscribe to the obligations set
  forth in this paragraph.
  
  
        5.1 RIGHT OF USE
  
  The Licensee is authorized to use the Software, without any limitation
  as to its fields of application, with it being hereinafter specified
  that this comprises:
  
     1. permanent or temporary reproduction of all or part of the Software
        by any or all means and in any or all form.
  
     2. loading, displaying, running, or storing the Software on any or
        all medium.
  
     3. entitlement to observe, study or test its operation so as to
        determine the ideas and principles behind any or all constituent
        elements of said Software. This shall apply when the Licensee
        carries out any or all loading, displaying, running, transmission
        or storage operation as regards the Software, that it is entitled
        to carry out hereunder.
  
  
        5.2 ENTITLEMENT TO MAKE CONTRIBUTIONS
  
  The right to make Contributions includes the right to translate, adapt,
  arrange, or make any or all modifications to the Software, and the right
  to reproduce the resulting software.
  
  The Licensee is authorized to make any or all Contributions to the
  Software provided that it includes an explicit notice that it is the
  author of said Contribution and indicates the date of the creation thereof.
  
  
        5.3 RIGHT OF DISTRIBUTION
  
  In particular, the right of distribution includes the right to publish,
  transmit and communicate the Software to the general public on any or
  all medium, and by any or all means, and the right to market, either in
  consideration of a fee, or free of charge, one or more copies of the
  Software by any means.
  
  The Licensee is further authorized to distribute copies of the modified
  or unmodified Software to third parties according to the terms and
  conditions set forth hereinafter.
  
  
          5.3.1 DISTRIBUTION OF SOFTWARE WITHOUT MODIFICATION
  
  The Licensee is authorized to distribute true copies of the Software in
  Source Code or Object Code form, provided that said distribution
  complies with all the provisions of the Agreement and is accompanied by:
  
     1. a copy of the Agreement,
  
     2. a notice relating to the limitation of both the Licensor's
        warranty and liability as set forth in Articles 8 and 9,
  
  and that, in the event that only the Object Code of the Software is
  redistributed, the Licensee allows effective access to the full Source
  Code of the Software at a minimum during the entire period of its
  distribution of the Software, it being understood that the additional
  cost of acquiring the Source Code shall not exceed the cost of
  transferring the data.
  
  
          5.3.2 DISTRIBUTION OF MODIFIED SOFTWARE
  
  If the Licensee makes any Contribution to the Software, the resulting
  Modified Software may be distributed under a license agreement other
  than this Agreement subject to compliance with the provisions of Article
  5.3.4.
  
  
          5.3.3 DISTRIBUTION OF EXTERNAL MODULES
  
  When the Licensee has developed an External Module, the terms and
  conditions of this Agreement do not apply to said External Module, that
  may be distributed under a separate license agreement.
  
  
          5.3.4 CREDITS
  
  Any Licensee who may distribute a Modified Software hereby expressly
  agrees to:
  
     1. indicate in the related documentation that it is based on the
        Software licensed hereunder, and reproduce the intellectual
        property notice for the Software,
  
     2. ensure that written indications of the Software intended use,
        intellectual property notice and license hereunder are included in
        easily accessible format from the Modified Software interface,
  
     3. mention, on a freely accessible website describing the Modified
        Software, at least throughout the distribution term thereof, that
        it is based on the Software licensed hereunder, and reproduce the
        Software intellectual property notice,
  
     4. where it is distributed to a third party that may distribute a
        Modified Software without having to make its source code
        available, make its best efforts to ensure that said third party
        agrees to comply with the obligations set forth in this Article .
  
  If the Software, whether or not modified, is distributed with an
  External Module designed for use in connection with the Software, the
  Licensee shall submit said External Module to the foregoing obligations.
  
  
          5.3.5 COMPATIBILITY WITH THE CeCILL AND CeCILL-C LICENSES
  
  Where a Modified Software contains a Contribution subject to the CeCILL
  license, the provisions set forth in Article 5.3.4 shall be optional.
  
  A Modified Software may be distributed under the CeCILL-C license. In
  such a case the provisions set forth in Article 5.3.4 shall be optional.
  
  
      Article 6 - INTELLECTUAL PROPERTY
  
  
        6.1 OVER THE INITIAL SOFTWARE
  
  The Holder owns the economic rights over the Initial Software. Any or
  all use of the Initial Software is subject to compliance with the terms
  and conditions under which the Holder has elected to distribute its work
  and no one shall be entitled to modify the terms and conditions for the
  distribution of said Initial Software.
  
  The Holder undertakes that the Initial Software will remain ruled at
  least by this Agreement, for the duration set forth in Article 4.2.
  
  
        6.2 OVER THE CONTRIBUTIONS
  
  The Licensee who develops a Contribution is the owner of the
  intellectual property rights over this Contribution as defined by
  applicable law.
  
  
        6.3 OVER THE EXTERNAL MODULES
  
  The Licensee who develops an External Module is the owner of the
  intellectual property rights over this External Module as defined by
  applicable law and is free to choose the type of agreement that shall
  govern its distribution.
  
  
        6.4 JOINT PROVISIONS
  
  The Licensee expressly undertakes:
  
     1. not to remove, or modify, in any manner, the intellectual property
        notices attached to the Software;
  
     2. to reproduce said notices, in an identical manner, in the copies
        of the Software modified or not.
  
  The Licensee undertakes not to directly or indirectly infringe the
  intellectual property rights of the Holder and/or Contributors on the
  Software and to take, where applicable, vis-\xe0-vis its staff, any and all
  measures required to ensure respect of said intellectual property rights
  of the Holder and/or Contributors.
  
  
      Article 7 - RELATED SERVICES
  
  7.1 Under no circumstances shall the Agreement oblige the Licensor to
  provide technical assistance or maintenance services for the Software.
  
  However, the Licensor is entitled to offer this type of services. The
  terms and conditions of such technical assistance, and/or such
  maintenance, shall be set forth in a separate instrument. Only the
  Licensor offering said maintenance and/or technical assistance services
  shall incur liability therefor.
  
  7.2 Similarly, any Licensor is entitled to offer to its licensees, under
  its sole responsibility, a warranty, that shall only be binding upon
  itself, for the redistribution of the Software and/or the Modified
  Software, under terms and conditions that it is free to decide. Said
  warranty, and the financial terms and conditions of its application,
  shall be subject of a separate instrument executed between the Licensor
  and the Licensee.
  
  
      Article 8 - LIABILITY
  
  8.1 Subject to the provisions of Article 8.2, the Licensee shall be
  entitled to claim compensation for any direct loss it may have suffered
  from the Software as a result of a fault on the part of the relevant
  Licensor, subject to providing evidence thereof.
  
  8.2 The Licensor's liability is limited to the commitments made under
  this Agreement and shall not be incurred as a result of in particular:
  (i) loss due the Licensee's total or partial failure to fulfill its
  obligations, (ii) direct or consequential loss that is suffered by the
  Licensee due to the use or performance of the Software, and (iii) more
  generally, any consequential loss. In particular the Parties expressly
  agree that any or all pecuniary or business loss (i.e. loss of data,
  loss of profits, operating loss, loss of customers or orders,
  opportunity cost, any disturbance to business activities) or any or all
  legal proceedings instituted against the Licensee by a third party,
  shall constitute consequential loss and shall not provide entitlement to
  any or all compensation from the Licensor.
  
  
      Article 9 - WARRANTY
  
  9.1 The Licensee acknowledges that the scientific and technical
  state-of-the-art when the Software was distributed did not enable all
  possible uses to be tested and verified, nor for the presence of
  possible defects to be detected. In this respect, the Licensee's
  attention has been drawn to the risks associated with loading, using,
  modifying and/or developing and reproducing the Software which are
  reserved for experienced users.
  
  The Licensee shall be responsible for verifying, by any or all means,
  the suitability of the product for its requirements, its good working
  order, and for ensuring that it shall not cause damage to either persons
  or properties.
  
  9.2 The Licensor hereby represents, in good faith, that it is entitled
  to grant all the rights over the Software (including in particular the
  rights set forth in Article 5).
  
  9.3 The Licensee acknowledges that the Software is supplied "as is" by
  the Licensor without any other express or tacit warranty, other than
  that provided for in Article 9.2 and, in particular, without any warranty 
  as to its commercial value, its secured, safe, innovative or relevant 
  nature.
  
  Specifically, the Licensor does not warrant that the Software is free
  from any error, that it will operate without interruption, that it will
  be compatible with the Licensee's own equipment and software
  configuration, nor that it will meet the Licensee's requirements.
  
  9.4 The Licensor does not either expressly or tacitly warrant that the
  Software does not infringe any third party intellectual property right
  relating to a patent, software or any other property right. Therefore,
  the Licensor disclaims any and all liability towards the Licensee
  arising out of any or all proceedings for infringement that may be
  instituted in respect of the use, modification and redistribution of the
  Software. Nevertheless, should such proceedings be instituted against
  the Licensee, the Licensor shall provide it with technical and legal
  assistance for its defense. Such technical and legal assistance shall be
  decided on a case-by-case basis between the relevant Licensor and the
  Licensee pursuant to a memorandum of understanding. The Licensor
  disclaims any and all liability as regards the Licensee's use of the
  name of the Software. No warranty is given as regards the existence of
  prior rights over the name of the Software or as regards the existence
  of a trademark.
  
  
      Article 10 - TERMINATION
  
  10.1 In the event of a breach by the Licensee of its obligations
  hereunder, the Licensor may automatically terminate this Agreement
  thirty (30) days after notice has been sent to the Licensee and has
  remained ineffective.
  
  10.2 A Licensee whose Agreement is terminated shall no longer be
  authorized to use, modify or distribute the Software. However, any
  licenses that it may have granted prior to termination of the Agreement
  shall remain valid subject to their having been granted in compliance
  with the terms and conditions hereof.
  
  
      Article 11 - MISCELLANEOUS
  
  
        11.1 EXCUSABLE EVENTS
  
  Neither Party shall be liable for any or all delay, or failure to
  perform the Agreement, that may be attributable to an event of force
  majeure, an act of God or an outside cause, such as defective
  functioning or interruptions of the electricity or telecommunications
  networks, network paralysis following a virus attack, intervention by
  government authorities, natural disasters, water damage, earthquakes,
  fire, explosions, strikes and labor unrest, war, etc.
  
  11.2 Any failure by either Party, on one or more occasions, to invoke
  one or more of the provisions hereof, shall under no circumstances be
  interpreted as being a waiver by the interested Party of its right to
  invoke said provision(s) subsequently.
  
  11.3 The Agreement cancels and replaces any or all previous agreements,
  whether written or oral, between the Parties and having the same
  purpose, and constitutes the entirety of the agreement between said
  Parties concerning said purpose. No supplement or modification to the
  terms and conditions hereof shall be effective as between the Parties
  unless it is made in writing and signed by their duly authorized
  representatives.
  
  11.4 In the event that one or more of the provisions hereof were to
  conflict with a current or future applicable act or legislative text,
  said act or legislative text shall prevail, and the Parties shall make
  the necessary amendments so as to comply with said act or legislative
  text. All other provisions shall remain effective. Similarly, invalidity
  of a provision of the Agreement, for any reason whatsoever, shall not
  cause the Agreement as a whole to be invalid.
  
  
        11.5 LANGUAGE
  
  The Agreement is drafted in both French and English and both versions
  are deemed authentic.
  
  
      Article 12 - NEW VERSIONS OF THE AGREEMENT
  
  12.1 Any person is authorized to duplicate and distribute copies of this
  Agreement.
  
  12.2 So as to ensure coherence, the wording of this Agreement is
  protected and may only be modified by the authors of the License, who
  reserve the right to periodically publish updates or new versions of the
  Agreement, each with a separate number. These subsequent versions may
  address new issues encountered by Free Software.
  
  12.3 Any Software distributed under a given version of the Agreement may
  only be subsequently distributed under the same version of the Agreement
  or a subsequent version.
  
  
      Article 13 - GOVERNING LAW AND JURISDICTION
  
  13.1 The Agreement is governed by French law. The Parties agree to
  endeavor to seek an amicable solution to any disagreements or disputes
  that may arise during the performance of the Agreement.
  
  13.2 Failing an amicable solution within two (2) months as from their
  occurrence, and unless emergency proceedings are necessary, the
  disagreements or disputes shall be referred to the Paris Courts having
  jurisdiction, by the more diligent Party.
  
  
  Version 1.0 dated 2006-09-05.
  