--- a/extra/control-oo/INDEX	Sat Feb 13 13:06:39 2010 +0000
+++ b/extra/control-oo/INDEX	Sat Feb 13 14:04:55 2010 +0000
@@ -83,7 +83,6 @@
   [..]
   @lti/inv
 Matrix Equation Solvers
-  are
   care
   dare
   dlyap

--- a/extra/control-oo/inst/are.m	Sat Feb 13 13:06:39 2010 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,133 +0,0 @@
-## Copyright (C) 1993, 1994, 1995, 2000, 2002, 2004, 2005, 2006, 2007
-##               Auburn University.  All rights reserved.
-##
-##
-## This program is free software; you can redistribute it and/or modify it
-## under the terms of the GNU General Public License as published by
-## the Free Software Foundation; either version 3 of the License, or (at
-## your option) any later version.
-##
-## This program 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 program; see the file COPYING.  If not, see
-## <http://www.gnu.org/licenses/>.
-
-## -*- texinfo -*-
-## @deftypefn {Function File} {@var{x} =} are (@var{a}, @var{b}, @var{c}, @var{opt})
-## Solve the Algebraic Riccati Equation
-## @iftex
-## @tex
-## $$
-## A^TX + XA - XBX + C = 0
-## $$
-## @end tex
-## @end iftex
-## @ifinfo
-## @example
-## a' * x + x * a - x * b * x + c = 0
-## @end example
-## @end ifinfo
-##
-## @strong{Inputs}
-## @noindent
-## for identically dimensioned square matrices
-## @table @var
-## @item a
-## @var{n} by @var{n} matrix;
-## @item b
-##   @var{n} by @var{n} matrix or @var{n} by @var{m} matrix; in the latter case
-##   @var{b} is replaced by @math{b:=b*b'};
-## @item c
-##   @var{n} by @var{n} matrix or @var{p} by @var{m} matrix; in the latter case
-##   @var{c} is replaced by @math{c:=c'*c};
-## @item opt
-## (optional argument; default = @code{"B"}):
-## String option passed to @code{balance} prior to ordered Schur decomposition.
-## @end table
-##
-## @strong{Output}
-## @table @var
-## @item x
-## solution of the @acronym{ARE}.
-## @end table
-##
-## @strong{Method}
-## Laub's Schur method (@acronym{IEEE} Transactions on
-## Automatic Control, 1979) is applied to the appropriate Hamiltonian
-## matrix.
-## @seealso{balance, dare}
-## @end deftypefn
-
-## Author: A. S. Hodel <a.s.hodel@eng.auburn.edu>
-## Created: August 1993
-
-## Adapted-By: Lukas Reichlin <lukas.reichlin@gmail.com>
-## Date: October 2009
-## Version: 0.1
-
-function x = are (a, b, c, opt = "B")
-
-  if (nargin < 3 || nargin > 4)
-    print_usage ();
-  endif
-
-  if (nargin == 4)
-    if (ischar (opt))
-      opt = upper (opt(1));
-      if (opt != "B" && opt != N && opt != "P" && opt != "S")
-        warning ("are: opt has invalid value ""%s""; setting to ""B""", opt);
-        opt = "B";
-      endif
-    else
-      warning ("are: invalid argument opt, setting to ""B""");
-      opt = "B";
-    endif
-  endif
-
-  n = issquare (a);
-  m = issquare (b);
-  p = issquare (c);
-
-  if (! n)
-    error ("are: matrix a is not square");
-  endif
-
-  if (! isctrb (a, b))
-    warning ("are: matrices a and b are not controllable");
-  endif
-
-  if (! m)
-    b = b * b';  # b must be symmetric
-    m = rows (b);
-  endif
-
-  if (! isobsv (a, c))
-    warning ("are: matrices a and c are not observable");
-  endif
-
-  ## to allow lqe design, don't force
-  ## b to be positive semi-definite
-
-  if (! p)
-    c = c' * c;  # c must be symmetric
-    p = rows (c);
-  endif
-
-  if (n != m || n != p)
-    error ("are: matrices a, b and c not conformably dimensioned");
-  endif
-
-  [d, h] = balance ([a, -b; -c, -a'], opt);
-  [u, s] = schur (h, "A");
-
-  u = d * u;
-  n1 = n + 1;
-  n2 = 2 * n;
-
-  x = u(n1:n2, 1:n) / u(1:n, 1:n);
-
-endfunction