--- a/scripts/control/system/is_stabilizable.m
+++ b/scripts/control/system/is_stabilizable.m
@@ -17,16 +17,16 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{retval}, @var{U}] =} is_stabilizable (@var{sys}, @var{tol})
-## @deftypefnx {Function File} {[@var{retval}, @var{U}] =} is_stabilizable (@var{a}, @var{b}, @var{tol})
+## @deftypefn {Function File} {[@var{retval}, @var{u}] =} is_stabilizable (@var{sys}, @var{tol})
+## @deftypefnx {Function File} {[@var{retval}, @var{u}] =} is_stabilizable (@var{a}, @var{b}, @var{tol})
 ## Logical check for system stabilizability (i.e., all unstable modes are controllable).
 ##
 ## Test for stabilizability is performed via an ordered Schur decomposition
-## that reveals the unstable subspace of the system @var{A} matrix.
+## that reveals the unstable subspace of the system @var{a} matrix.
 ##
-## Returns @code{retval} = 1 if the system, @code{a}, is stabilizable,
-## if the pair  (@code{a}, @code{b}) is stabilizable, or 0 if not.
-## @code{U} = orthogonal basis of controllable subspace.
+## Returns @code{retval} = 1 if the system, @var{a}, is stabilizable,
+## if the pair  (@var{a}, @var{b}) is stabilizable, or 0 if not.
+## @var{u} = orthogonal basis of controllable subspace.
 ##
 ## Controllable subspace is determined by applying Arnoldi iteration with
 ## complete re-orthogonalization to obtain an orthogonal basis of the