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| HOL DISTRIBUTION DIRECTORY: Licence					|
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This directory contains the TeX source for the optional HOL licence agreement.

HOL is a public domain system available for a nominal distribution fee. It
is based on code written, in alphabetical order, by Mike Gordon, Gerard Huet
(and others at Inria), Tom Melham, Robin Milner, Lockwood Morris, Malcolm
Newey, Larry Paulson and Chris Wadsworth.

Some users have asked to be issued with a HOL licence.  This is to legitimate
their use of the system for commercial purposes.  After consultation with
Robin Milner and the Cambridge University computing service (who have
experience with software licencing), the licence agreement in this directory
below was produced. The primary aims of the licence are:

   * to prevent us being `ripped off' or sued;

   * to prevent people claiming to have done a proof using HOL when 
     in fact they used their own insecure modifications of it.
     (in this case the licence merely requires the system to be called 
     something else, it does not prevent such modifications being made).

The signing of the licence is optional, but encouraged. Users of HOL are free
to redistribute the system to others provided they let Mike Gordon know in
writing. The simplest way to do this is to ask the party to whom HOL is given
to sign the licence and send it to Mike.
