In short, scmail is distributed under so called "BSD license",
that is, as far as you retain the copyrignt notice and disclaimer below,
you can use, copy, modify and redistribute your modification freely.
The formal term is specified in each copyright notices.


Copyright and condition of use of main portion of the source:
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  Copyright (c) 2002-2004 Satoru Takabayashi, All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:

   1. Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.

   2. Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.

   3. Neither the name of the authors nor the names of its contributors
      may be used to endorse or promote products derived from this
      software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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Copyright of scbayes.in, scmail/bayesian-filter.scm -------------------------

;;;  Copyright(C) 2003 by Shiro Kawai (shiro@acm.org)
;;;
;;;  Permission to use, copy, modify, distribute this software and
;;;  accompanying documentation for any purpose is hereby granted,
;;;  provided that existing copyright notices are retained in all
;;;  copies and that this notice is included verbatim in all
;;;  distributions.
;;;  This software is provided as is, without express or implied
;;;  warranty.  In no circumstances the author(s) shall be liable
;;;  for any damages arising out of the use of this software.
