Copyright (c) 1986 by University of Toronto. Written by Henry Spencer. Not
derived from licensed software.

Permission is granted to anyone to use this software for any purpose
on any computer system, and to redistribute it freely, subject to the
following restrictions:

   1. The author is not responsible for the consequences of use of this
   software, no matter how awful, even if they arise from defects in it.

   2. The origin of this software must not be misrepresented, either by
   explicit claim or by omission.

   3. Altered versions must be plainly marked as such, and must not be
   misrepresented as being the original software.
