diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,674 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://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 <http://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
+<http://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
+<http://www.gnu.org/philosophy/why-not-lgpl.html>.
diff --git a/Language/SMTLib2/Debug.hs b/Language/SMTLib2/Debug.hs
new file mode 100644
--- /dev/null
+++ b/Language/SMTLib2/Debug.hs
@@ -0,0 +1,341 @@
+{-# LANGUAGE PolyKinds,DataKinds,ScopedTypeVariables #-}
+module Language.SMTLib2.Debug
+       (DebugBackend(),
+        debugBackend,
+        namedDebugBackend,
+        debugBackend') where
+
+import Language.SMTLib2.Internals.Backend
+import Language.SMTLib2.Internals.Type hiding (Constr,Field)
+import qualified Language.SMTLib2.Internals.Type.List as List
+import Language.SMTLib2.Internals.Expression (Expression(Let),LetBinding(..),mapExpr)
+import Language.SMTLib2.Pipe.Internals
+
+import qualified Data.AttoLisp as L
+import System.Console.ANSI
+import System.IO
+import Control.Monad.Trans
+import Control.Monad (when)
+import Data.Foldable
+import Data.Map (Map)
+import qualified Data.Map as Map
+import qualified Data.Text as T
+import Data.Functor.Identity
+import Data.Typeable
+import Data.GADT.Show
+import Data.GADT.Compare
+
+import Data.Dependent.Map (DMap)
+import qualified Data.Dependent.Map as DMap
+
+debugBackend :: (Backend b,MonadIO (SMTMonad b)) => b -> DebugBackend b
+debugBackend b = DebugBackend b stderr (Just 0) Nothing True
+                 Map.empty DMap.empty DMap.empty DMap.empty
+                 DMap.empty DMap.empty Map.empty emptyTypeRegistry
+
+namedDebugBackend :: (Backend b,MonadIO (SMTMonad b)) => String -> b -> DebugBackend b
+namedDebugBackend name b = DebugBackend b stderr (Just 0) (Just name) True
+                           Map.empty DMap.empty DMap.empty DMap.empty
+                           DMap.empty DMap.empty Map.empty emptyTypeRegistry
+
+debugBackend' :: (Backend b,MonadIO (SMTMonad b))
+              => Bool -- ^ Display line number
+              -> Bool -- ^ Use color codes
+              -> Maybe String -- ^ Prefix name
+              -> Handle -- ^ Output handle
+              -> b
+              -> DebugBackend b
+debugBackend' lines color name h b
+  = DebugBackend b h (if lines then Just 0 else Nothing) name color
+    Map.empty DMap.empty DMap.empty DMap.empty
+    DMap.empty DMap.empty Map.empty emptyTypeRegistry
+
+data DebugBackend (b :: *)
+  = (Backend b,MonadIO (SMTMonad b))
+    => DebugBackend { debugBackend'' :: b
+                    , debugHandle :: Handle
+                    , debugLines :: Maybe Integer
+                    , debugPrefix :: Maybe String
+                    , debugUseColor :: Bool
+                    , debugNames :: Map String Int
+                    , debugVars :: DMap (Var b) (UntypedVar T.Text)
+                    , debugQVars :: DMap (QVar b) (UntypedVar T.Text)
+                    , debugFuns :: DMap (Fun b) (UntypedFun T.Text)
+                    , debugFVars :: DMap (FunArg b) (UntypedVar T.Text)
+                    , debugLVars :: DMap (LVar b) (UntypedVar T.Text)
+                    , debugCIds :: Map (ClauseId b) T.Text
+                    , debugDatatypes :: TypeRegistry T.Text T.Text T.Text
+                    }
+  deriving Typeable
+
+outputLisp :: DebugBackend (b:: *) -> L.Lisp -> SMTMonad b (DebugBackend b)
+outputLisp b lsp
+  = outputLines b False (lines $ show lsp)
+
+outputLines :: DebugBackend b -> Bool -> [String]
+            -> SMTMonad b (DebugBackend b)
+outputLines b@(DebugBackend {}) isComment
+  = foldlM (\b' line -> outputLine b' isComment line) b
+
+outputLine :: DebugBackend b -> Bool -> String
+           -> SMTMonad b (DebugBackend b)
+outputLine b@(DebugBackend {}) isComment str = do
+  case debugPrefix b of
+    Nothing -> return ()
+    Just prf -> do
+      when (debugUseColor b) $ liftIO $ hSetSGR (debugHandle b) [Reset,SetColor Foreground Dull Cyan]
+      liftIO $ hPutStr (debugHandle b) prf
+  nline <- case debugLines b of
+             Nothing -> return Nothing
+             Just line -> do
+               when (debugUseColor b) $ liftIO $ hSetSGR (debugHandle b) [Reset,SetColor Foreground Dull Red]
+               let line_str = show line
+                   line_str_len = length line_str
+                   line_str' = replicate (4-line_str_len) ' '++line_str++" "
+               liftIO $ hPutStr (debugHandle b) line_str'
+               return (Just (line+1))
+  if isComment
+    then do
+      when (debugUseColor b) $ liftIO $ hSetSGR (debugHandle b) [Reset,SetColor Foreground Dull White]
+      liftIO $ hPutStrLn (debugHandle b) $ ';':' ':str
+    else do
+      when (debugUseColor b) $ liftIO $ hSetSGR (debugHandle b) [Reset,SetColor Foreground Dull Green]
+      liftIO $ hPutStrLn (debugHandle b) str
+  when (debugUseColor b) $ liftIO $ hSetSGR (debugHandle b) [Reset]
+  liftIO $ hFlush (debugHandle b)
+  return $ b { debugLines = nline }
+
+outputResponse :: DebugBackend b -> String -> SMTMonad b ()
+outputResponse b@(DebugBackend {}) str = do
+  when (debugUseColor b) $ liftIO $ hSetSGR (debugHandle b) [Reset,SetColor Foreground Dull Blue]
+  liftIO $ hPutStrLn (debugHandle b) str
+  when (debugUseColor b) $ liftIO $ hSetSGR (debugHandle b) [Reset]
+  liftIO $ hFlush (debugHandle b)
+
+deriving instance Backend b => GShow (Expr (DebugBackend b))
+deriving instance Backend b => GEq (Expr (DebugBackend b))
+deriving instance Backend b => GCompare (Expr (DebugBackend b))
+deriving instance Backend b => GetType (Expr (DebugBackend b))
+
+instance (Backend b) => Backend (DebugBackend b) where
+  type SMTMonad (DebugBackend b) = SMTMonad b
+  newtype Expr (DebugBackend b) t = DebugExpr (Expr b t)
+  type Var (DebugBackend b) = Var b
+  type QVar (DebugBackend b) = QVar b
+  type Fun (DebugBackend b) = Fun b
+  type FunArg (DebugBackend b) = FunArg b
+  type LVar (DebugBackend b) = LVar b
+  type ClauseId (DebugBackend b) = ClauseId b
+  type Model (DebugBackend b) = Model b
+  type Proof (DebugBackend b) = Proof b
+  setOption opt b = do
+    b1 <- outputLisp b (renderSetOption opt)
+    ((),nb) <- setOption opt (debugBackend'' b1)
+    return ((),b1 { debugBackend'' = nb })
+  getInfo info b = do
+    b1 <- outputLisp b (renderGetInfo info)
+    (res,nb) <- getInfo info (debugBackend'' b1)
+    outputResponse b1 (case info of
+                        SMTSolverName -> res
+                        SMTSolverVersion -> res)
+    return (res,b1 { debugBackend'' = nb })
+  declareVar tp name b = do
+    let (sym,req,nnames) = renderDeclareVar (debugNames b) tp name
+        b1 = b { debugNames = nnames }
+    b2 <- outputLisp b1 req
+    (rvar,nb) <- declareVar tp name (debugBackend'' b2)
+    return (rvar,b2 { debugBackend'' = nb
+                    , debugVars = DMap.insertWith const rvar
+                                  (UntypedVar sym tp) (debugVars b2) })
+  defineFun name args (DebugExpr body) b = do
+    let (sym,req,nnames) = renderDefineFun
+                           (\fv -> case DMap.lookup fv (debugFVars b) of
+                             Just (UntypedVar n _) -> L.Symbol n)
+                           (renderExpr b)
+                           (debugNames b) name args body
+        b1 = b { debugNames = nnames }
+    b2 <- outputLisp b1 req
+    (rvar,nb) <- defineFun name args body (debugBackend'' b2)
+    let (argtp,rtp) = getFunType rvar
+    return (rvar,b2 { debugBackend'' = nb
+                    , debugFuns = DMap.insertWith const rvar
+                                  (UntypedFun sym argtp rtp) (debugFuns b2) }) 
+  createFunArg tp name b = do
+    let name' = case name of
+          Just n -> n
+          Nothing -> "fv"
+        (name'',nnames) = genName' (debugNames b) name'
+    (fv,nb) <- createFunArg tp name (debugBackend'' b)
+    return (fv,b { debugBackend'' = nb
+                 , debugNames = nnames
+                 , debugFVars = DMap.insert fv (UntypedVar name'' tp) (debugFVars b) })
+  toBackend expr b = do
+    (expr',nb) <- toBackend (runIdentity $ mapExpr return return return return return (\(DebugExpr e) -> return e) expr)
+                  (debugBackend'' b)
+    return (DebugExpr expr',b { debugBackend'' = nb })
+  fromBackend b (DebugExpr e) = runIdentity $ mapExpr return return return return return (return.DebugExpr) $
+                                fromBackend (debugBackend'' b) e
+  assert (DebugExpr expr) b = do
+    let l = renderExpr b expr
+    b1 <- outputLisp b (L.List [L.Symbol "assert",l])
+    ((),nb) <- assert expr (debugBackend'' b1)
+    return ((),b1 { debugBackend'' = nb })
+  assertPartition (DebugExpr expr) part b = do
+    let l = renderExpr b expr
+    b1 <- outputLisp b (L.List [L.Symbol "assert"
+                               ,L.List [L.Symbol "!"
+                                  ,l
+                                  ,L.Symbol ":interpolation-group"
+                                  ,L.Symbol (case part of
+                                               PartitionA -> "partA"
+                                               PartitionB -> "partB")]])
+    ((),nb) <- assertPartition expr part (debugBackend'' b1)
+    return ((),b1 { debugBackend'' = nb })
+  assertId (DebugExpr expr) b = do
+    let l = renderExpr b expr
+        (name,nnames) = genName' (debugNames b) "cid"
+        b1 = b { debugNames = nnames }
+    b2 <- outputLisp b1 (L.List [L.Symbol "assert"
+                                ,L.List [L.Symbol "!",l
+                                        ,L.Symbol ":named"
+                                        ,L.Symbol name]])
+    (cid,nb) <- assertId expr (debugBackend'' b2)
+    return (cid,b2 { debugBackend'' = nb
+                   , debugCIds = Map.insert cid name (debugCIds b2) })
+  interpolate b = do
+    b1 <- outputLisp b (L.List [L.Symbol "get-interpolant",L.List [L.Symbol "partA"]])
+    (res,nb) <- interpolate (debugBackend'' b)
+    outputResponse b1 (show $ renderExpr b1 res)
+    return (DebugExpr res,b1 { debugBackend'' = nb })
+  checkSat tactic limits b = do
+    b1 <- outputLisp b (renderCheckSat tactic limits)
+    (res,nb) <- checkSat tactic limits (debugBackend'' b)
+    outputResponse b1 $ case res of
+      Sat -> "sat"
+      Unsat -> "unsat"
+      Unknown -> "unknown"
+    return (res,b1 { debugBackend'' = nb })
+  getValue (DebugExpr expr) b = do
+    let l = renderExpr b expr
+    b1 <- outputLisp b (L.List [L.Symbol "get-value"
+                               ,L.List [l]])
+    (res,nb) <- getValue expr (debugBackend'' b1)
+    str <- valueToLisp (\dt con -> case Map.lookup (AnyConstr dt con) (revConstructors $ debugDatatypes b1) of
+                          Just sym -> return $ L.Symbol sym) res
+    outputResponse b1 (show str)
+    return (res,b1 { debugBackend'' = nb })
+  declareFun argtp rtp name b = do
+    let (sym,req,nnames) = renderDeclareFun (debugNames b) argtp rtp name
+        b1 = b { debugNames = nnames }
+    b2 <- outputLisp b1 req
+    (rvar,nb) <- declareFun argtp rtp name (debugBackend'' b2)
+    return (rvar,b2 { debugBackend'' = nb
+                    , debugFuns = DMap.insert rvar (UntypedFun sym argtp rtp) (debugFuns b2) })
+  declareDatatypes coll b = do
+    let (req,nnames,nreg) = renderDeclareDatatype (debugNames b) (debugDatatypes b) coll
+        b1 = b { debugNames = nnames
+               , debugDatatypes = nreg }
+    b2 <- outputLisp b1 req
+    (res,nb) <- declareDatatypes coll (debugBackend'' b2)
+    return (res,b2 { debugBackend'' = nb })
+  createQVar tp name b = do
+    let name' = case name of
+          Just n -> n
+          Nothing -> "qv"
+        (name'',nnames) = genName' (debugNames b) name'
+    (rvar,nb) <- createQVar tp name (debugBackend'' b)
+    return (rvar,b { debugBackend'' = nb
+                   , debugNames = nnames
+                   , debugQVars = DMap.insert rvar
+                                  (UntypedVar name'' tp)
+                                  (debugQVars b) })
+  exit b = do
+    b1 <- outputLisp b (L.List [L.Symbol "exit"])
+    ((),nb) <- exit (debugBackend'' b1)
+    return ((),b1 { debugBackend'' = nb })
+  push b = do
+    b1 <- outputLisp b (L.List [L.Symbol "push"])
+    ((),nb) <- push (debugBackend'' b1)
+    return ((),b1 { debugBackend'' = nb })
+  pop b = do
+    b1 <- outputLisp b (L.List [L.Symbol "pop"])
+    ((),nb) <- pop (debugBackend'' b1)
+    return ((),b1 { debugBackend'' = nb })
+  defineVar name (DebugExpr expr) b = do
+    let l = renderExpr b expr
+        tp = getType expr
+        (sym,req,nnames) = renderDefineVar (debugNames b) tp name l
+        b1 = b { debugNames = nnames }
+    b2 <- outputLisp b1 req
+    (res,nb) <- defineVar name expr (debugBackend'' b2)
+    return (res,b2 { debugBackend'' = nb
+                   , debugVars = DMap.insert res (UntypedVar sym tp)
+                                 (debugVars b2) })
+  getUnsatCore b = do
+    b1 <- outputLisp b (L.List [L.Symbol "get-unsat-core"])
+    (res,nb) <- getUnsatCore (debugBackend'' b1)
+    let b2 = b1 { debugBackend'' = nb }
+    outputResponse b2 (show $ L.List [ L.Symbol ((debugCIds b2) Map.! cid)
+                                     | cid <- res ])
+    return (res,b2)
+  getModel b = do
+    b1 <- outputLisp b (L.List [L.Symbol "get-model"])
+    (mdl,nb) <- getModel (debugBackend'' b1)
+    let b2 = b1 { debugBackend'' = nb }
+    outputResponse b2 (show mdl)
+    return (mdl,b2)
+  modelEvaluate mdl (DebugExpr e) b = do
+    (res,nb) <- modelEvaluate mdl e (debugBackend'' b)
+    return (res,b { debugBackend'' = nb })
+  getProof b = do
+    b1 <- outputLisp b (L.List [L.Symbol "get-proof"])
+    (proof,nb) <- getProof (debugBackend'' b1)
+    let b2 = b1 { debugBackend'' = nb }
+    outputResponse b2 (show proof)
+    return (proof,b2)
+  simplify (DebugExpr expr) b = do
+    let l = renderExpr b expr
+    b1 <- outputLisp b (L.List [L.Symbol "simplify",l])
+    (res,nb) <- simplify expr (debugBackend'' b1)
+    let b2 = b1 { debugBackend'' = nb }
+    outputResponse b2 (show $ renderExpr b2 res)
+    return (DebugExpr res,b2)
+  comment msg b = do
+    b1 <- outputLine b True msg
+    ((),nb) <- comment msg (debugBackend'' b1)
+    let b2 = b1 { debugBackend'' = nb }
+    return ((),b2)
+    
+renderExpr :: (Backend b) => DebugBackend b -> Expr b tp
+           -> L.Lisp
+renderExpr b expr
+  = runIdentity $ exprToLispWith
+    (\v -> case DMap.lookup v (debugVars nb) of
+             Just (UntypedVar r _) -> return $ L.Symbol r)
+    (\v -> case DMap.lookup v (debugQVars nb) of
+             Just (UntypedVar r _) -> return $ L.Symbol r)
+    (\v -> case DMap.lookup v (debugFuns nb) of
+             Just (UntypedFun r _ _) -> return $ L.Symbol r)
+    (\dt con -> case Map.lookup (AnyConstr dt con) (revConstructors $ debugDatatypes nb) of
+             Just sym -> return $ L.Symbol sym)
+    (\dt con -> case Map.lookup (AnyConstr dt con) (revConstructors $ debugDatatypes nb) of
+             Just sym -> return $ L.Symbol $ T.append "is-" sym)
+    (\dt f -> case Map.lookup (AnyField dt f) (revFields $ debugDatatypes nb) of
+             Just sym -> return $ L.Symbol sym)
+    (\v -> case DMap.lookup v (debugFVars nb) of
+             Just (UntypedVar r _) -> return $ L.Symbol r)
+    (\v -> case DMap.lookup v (debugLVars nb) of
+             Just (UntypedVar r _) -> return $ L.Symbol r)
+    (return . renderExpr nb) expr'
+  where
+    expr' = fromBackend (debugBackend'' b) expr
+    nb = case expr' of
+      Let args _ -> runIdentity $ List.foldM (\cb var -> do
+                                                 let (name,nnames) = genName' (debugNames cb) "var"
+                                                 return cb { debugNames = nnames
+                                                           , debugLVars = DMap.insert (letVar var)
+                                                                          (UntypedVar name (getType $ letVar var))
+                                                                          (debugLVars cb)
+                                                           }
+                                             ) b args
+      _ -> b
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/smtlib2-debug.cabal b/smtlib2-debug.cabal
new file mode 100644
--- /dev/null
+++ b/smtlib2-debug.cabal
@@ -0,0 +1,20 @@
+Name:           smtlib2-debug
+Version:        1.0
+Author:         Henning Günther <guenther@forsyte.at>
+Maintainer:     guenther@forsyte.at
+Synopsis:       Dump the communication with an SMT solver for debugging purposes.
+Stability:      provisional
+Category:       SMT, Formal Methods, Theorem Provers, Symbolic Computation
+License:        GPL-3
+License-File:   LICENSE
+Build-Type:     Simple
+Cabal-Version:  >=1.4
+
+Library
+  Build-Depends:        base >= 4 && < 5, smtlib2 >= 1.0 && < 1.1, smtlib2-pipe >= 1.0 && < 1.1,
+                        ansi-terminal >= 0.5, atto-lisp, mtl,containers,text, dependent-map >= 0.2,
+                        dependent-sum
+  Extensions:		FlexibleContexts,TypeFamilies,GADTs,ExistentialQuantification,OverloadedStrings,DeriveDataTypeable,GeneralizedNewtypeDeriving,StandaloneDeriving,FlexibleInstances
+  GHC-Options: -fwarn-unused-imports
+  Exposed-Modules:
+    Language.SMTLib2.Debug