Screamer
A portable efficient implementation of nondeterministic Common Lisp

Written by:

  Jeffrey Mark Siskind (Department of Computer Science, University of Toronto)
  David Allen McAllester (MIT Artificial Intelligence Laboratory)

Copyright 1991 Massachusetts Institute of Technology. All rights reserved.
Copyright 1992, 1993 University of Pennsylvania. All rights reserved.
Copyright 1993 University of Toronto. All rights reserved.

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright and authorship notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

HISTORICAL NOTE: Screamer was originally licensed under the following terms, but
Jeffrey Siskind kindly gave permission to relicense and distribute it under the
above 1-clause MIT license -- which is a good thing especially since the mailing
lists mentioned below are long since defunct:

 --old license term start--
 You are free to use, copy and distribute this software provided that:
  1. You report *ALL* bugs to Bug-Screamer@AI.MIT.EDU whether or not you need
     them fixed. Include the version number (3.20) in the message.
  2. You report *ALL* bugs that you fixed to Bug-Screamer@AI.MIT.EDU. Include
     the version number (3.20) in the message.
  3. Every time you run Screamer on a machine or using a Lisp compiler not
     mentioned below, you send a message stating the new environment and the
     version number (3.20) to Bug-Screamer@AI.MIT.EDU.
  4. You inform us that you obtained a copy of Screamer by sending a message to
     Info-Screamer-Request@AI.MIT.EDU to be put on the Info-Screamer@AI.MIT.EDU
     mailing list.
  --old license terms end--

Happy Constraining!