MPFR was downloaded from http://www.mpfr.org/.

Copyright 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation.
Contributed by the Spaces project, INRIA Lorraine.

This library is distributed under the terms of the GNU Lesser General
Public License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

On Debian systems, a copy of the licence is located in file
/usr/share/common-licenses/LGPL-2.1.