Copyright for derivations source package in Focal

This is derivations, written and maintained
by Thaddeus H. Black 
on Fri, 04 Nov 2005 00:00:00 +0000.

The original source can always be found at:
        http://ftp.debian.org/debian/pool/main/d/derivations/

Copyright (C) 1983-2018  Thaddeus H. Black

License:

  This book, its source and all the files packaged with them are free
  software; you can redistribute them and/or modify them under the terms
  of the GNU General Public License, version 2, as published by the Free
  Software Foundation.

  This software is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this package; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St., Fifth Floor,
  Boston, MA 02110-1301, USA.

On Debian systems, the complete text of the GNU General
Public License can be found in `/usr/share/common-licenses/GPL-2'.