			    SWI-Prolog LICENCE
			(Clarified 6 August 1990)

Copyright (C) 1990 Jan Wielemaker, University of Amsterdam.  Everyone is
permitted to copy and distribute verbatim copies of  this  licence,  but
changing  it  is not allowed.  You can also use this wording to make the
terms for other programs.  This licence is a based on (but not equal to)
the General Public Licence of the Free Software Foundation.

This licence agreement is intended to give anyone  the  right  to  share
SWI-Prolog for non-commercial use.  To make sure that you get the rights
we  want you to have, we need to make restrictions that forbid anyone to
deny you these rights or to ask you to surrender the rights.  Hence this
licence agreement.

Specifically, we want to make sure that you have the right to give  away
copies of SWI-Prolog, that you receive source code or else can get it if
you  want  it, that you can change SWI-Prolog or use pieces of it in new
free programs, and that you know you can do these things.

To make sure that everyone has such rights, we have  to  forbid  you  to
deprive  anyone  else  of  these rights.  For example, if you distribute
copies of SWI-Prolog, you must give the recipients all the  rights  that
you  have.   You  must  make sure that they, too, receive or can get the
source code.  And you must give them a verbatim copy of this licence  to
tell them their rights.

Also, for our own protection, we must make certain that  everyone  finds
out that there is no warranty for SWI-Prolog.  If SWI-Prolog is modified
by  someone else and passed on, we want its recipients to know that what
they have is not what we distributed, so that any problems introduced by
others will not reflect on our reputation.

Therefore we (Jan  Wielemaker  and  the  Department  of  Social  Science
Informatics  (SWI)  of  the  University of Amsterdam) make the following
terms which say what you must do to be allowed to distribute  or  change
SWI-Prolog.


			  COPYING POLICIES

  1.  You may  copy  and  distribute  verbatim copies  of the SWI-Prolog
source code  as  you receive  it, on any   medium,   provided that   you
conspicuously  and appropriately publish on each  copy a valid copyright
notice "Copyright (C)  1990  Jan Wielemaker" and the  author's  address;
keep   intact the  notices   on  all files  that  refer  to this Licence
Agreement  and  to  the  absence of  any warranty;  and   give any other
recipients  of the SWI-Prolog program a  copy of this  Licence Agreement
along  with  the program.  You  may  charge a  distribution fee for  the
physical act of transferring a copy.

  2.  You may modify your copy or copies of SWI-Prolog  source  code  or
any  portion of it, and copy and distribute such modifications under the
terms of Paragraph 1 above, provided that you also do the following:

    a) cause the modified files to carry prominent notices stating  that
    you changed the files and the date of any change; and

    b) cause the whole of any work that you distribute or publish,  that
    in whole or in part contains or is a derivative of SWI-Prolog or any
    part  thereof,  to  be licensed at no charge to all third parties on
    terms identical to those contained in this Licence Agreement (except
    that you may choose to grant more extensive warranty  protection  to
    some or all third parties, at your option).

    c) if the modified program serves as an interactive  Prolog  system,
    cause  it  when  started  running  in the simplest and usual way, to
    print an announcement including a valid copyright notice  "Copyright
    (C)  1990  University  of  Amsterdam", and informing the user how to
    view a copy of this Licence Agreement.

    d) you may charge  a  distribution  fee  for  the  physical  act  of
    transferring  a  copy,  and  you  may  at your option offer warranty
    protection in exchange for a fee.

Mere aggregation of another unrelated program with this program (or  its
derivative)  on  a  volume  of a storage or distribution medium does not
bring the other program under the scope of these terms.

  3.  You may copy and distribute SWI-Prolog (or a portion or derivative
of it, under Paragraph 2) in object code or executable  form  under  the
terms  of  Paragraphs 1 and 2 above provided that you also do one of the
following:

    a) accompany it with  the  complete  corresponding  machine-readable
    source code, which must be distributed under the terms of Paragraphs
    1 and 2 above; or,

    b) accompany it with a written  offer,  valid  for  at  least  three
    years,  to  give any third party free (except for a nominal shipping
    charge) a complete machine-readable copy of the corresponding source
    code, to be distributed under the terms of Paragraphs 1 and 2 above;
    or,

    c) accompany it with the information you received as  to  where  the
    corresponding  source  code  may  be obtained.  (This alternative is
    allowed only for noncommercial distribution and only if you received
    the program in object code or executable form alone.)

For an executable file, complete source code means all the  source  code
for  all  modules  it contains; but, as a special exception, it need not
include source code  for  modules  which  are  standard  libraries  that
accompany the operating system on which the executable file runs.

  4.  You may not copy, sublicense, distribute  or  transfer  SWI-Prolog
except  as expressly provided under this Licence Agreement.  Any attempt
otherwise to copy, sublicense, distribute or transfer SWI-Prolog is void
and your rights to use SWI-Prolog under this Licence Agreement shall  be
automatically  terminated.   However, parties who have received computer
software programs from you with this Licence  Agreement  will  not  have
their  licences  terminated  so  long  as  such  parties  remain in full
compliance.

  5.  If you wish to incorporate parts of SWI-Prolog into other programs
or distribute Prolog programs running on SWI-Prolog  whose  distribution
conditions  are  different,  contact the author.  We have not yet worked
out a simple rule that can be stated here,  but  we  will  often  permit
this.

  6.  If you base research on SWI-Prolog and publish on  this  research,
you   must   include  appropriate  acknowledgements  and  references  to
SWI-Prolog in your publication.

Your comments and suggestions about  our  licensing  policies  and  this
software are welcome!  Please contact the author, Jan Wielemaker, Social
Science  Informatics  (SWI),  University  of Amsterdam, Roetersstraat 15
1018 WB Amsterdam, The Netherlands.  E-mail: jan@swi.psy.uva.nl


			   NO WARRANTY

  BECAUSE SWI-PROLOG IS LICENSED FREE OF CHARGE, WE  PROVIDE  ABSOLUTELY
NO  WARRANTY,  TO  THE  EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
OTHERWISE STATED IN WRITING, THE UNIVERSITY OF AMSTERDAM, JAN WIELEMAKER
AND/OR OTHER PARTIES PROVIDE SWI-PROLOG "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 SWI-PROLOG PROGRAM PROVE DEFECTIVE, YOU
ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW WILL  THE  UNIVERSITY  OF
AMSTERDAM,  JAN  WIELEMAKER,  AND/OR  ANY OTHER PARTY WHO MAY MODIFY AND
REDISTRIBUTE SWI-PROLOG  AS  PERMITTED  ABOVE,  BE  LIABLE  TO  YOU  FOR
DAMAGES,  INCLUDING  ANY  LOST  PROFITS,  LOST MONIES, OR OTHER SPECIAL,
INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR  INABILITY
TO USE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED
INACCURATE  OR  LOSSES  SUSTAINED  BY  THIRD PARTIES OR A FAILURE OF THE
PROGRAM TO OPERATE WITH PROGRAMS NOT DISTRIBUTED BY THE UNIVERSITY BY OF
AMSTERDAM) THE PROGRAM, EVEN IF YOU HAVE BEEN ADVISED OF THE POSSIBILITY
OF SUCH DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY.


========================================================================
    Notification of Acceptance of the SWI-Prolog Licence Agreement

I  have  read  the  SWI-Prolog  licence  agreement  and  understand  the
conditions   of  this  licence  and  the  no-warranty  terms.   Any  act
conflicting with this licence agreement makes the agreement void.

Name:___________________________________________

Institution:____________________________________

Address:________________________________________

	________________________________________

	________________________________________

E-mail: _____________________


I obtained a copy of SWI-Prolog from: _________________________________
This copy is:

	O An unmodified version
	O A modified version

If it concerns a modified version:

Author(s) that implemented the modifications:

	_______________________________________________________________

Description of the modifications:

	_______________________________________________________________

	_______________________________________________________________

	_______________________________________________________________

	_______________________________________________________________

	_______________________________________________________________


I would like to be noticed of new releases and bug fixes

	O  yes	(Notification is only possible by E-mail)
	O  no

I will mainly be using SWI-Prolog for (curiosity only; you do not have
to answer this question):

	O  Research in logic programming
	O  Research in Prolog environments
	O  Teaching Prolog
	O  Other:

	_______________________________________________________________

	_______________________________________________________________

	_______________________________________________________________

	_______________________________________________________________


Return this form to by E-mail or surface mail to:

	Jan Wielemaker
	Social Science Informatics (SWI)
	Herengracht 196
	1016 BS  Amsterdam
	The Netherlands
	E-mail: jan@swi.psy.uva.nl
