Following conceptual and mathematical guidelines by John McCarty (http://www-formal.stanford.edu/jmc/basis1/node7.html):
Original implementation of the Amb class (now a module) by Jim Weirich (http://onestepback.org/articles/callcc/amb/index.html). Copyright notice:
# Copyright 2006 by Jim Weirich (jim@weirichhouse.org). All rights reserved.
# Permission is granted for use, modification and distribution as
# long as the above copyright notice is included.
Original implementation of the amb operator by Eric Kidd (http://www.randomhacks.net/articles/2005/10/11/amb-operator). No specific copyright notice.
Further improvements by Jean-Denis Vauguet jd@vauguet.fr for the Amb gem.
Otherwise stated in this file, code is made available under the MIT license (see MIT-LICENSE file).
Thank you very much for your work.