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diff --git a/ast/pal/palEcmat.c b/ast/pal/palEcmat.c
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+/*
+*+
+*  Name:
+*     palEcmat
+
+*  Purpose:
+*     Form the equatorial to ecliptic rotation matrix - IAU 2006
+*     precession model.
+
+*  Language:
+*     Starlink ANSI C
+
+*  Type of Module:
+*     Library routine
+
+*  Invocation:
+*     palEcmat( double date, double rmat[3][3] )
+
+*  Arguments:
+*     date = double (Given)
+*        TT as Modified Julian Date (JD-2400000.5). The difference
+*        between TT and TDB is of the order of a millisecond or two
+*        (i.e. about 0.02 arc-seconds).
+*     rmat = double[3][3] (Returned)
+*        Rotation matrix
+
+*  Description:
+*     The equatorial to ecliptic rotation matrix is found and returned.
+*     The matrix is in the sense   V(ecl)  =  RMAT * V(equ);  the
+*     equator, equinox and ecliptic are mean of date.
+
+*  Authors:
+*     PTW: Pat Wallace (STFC)
+*     DSB: David Berry (JAC, Hawaii)
+*     {enter_new_authors_here}
+
+*  History:
+*     2012-02-10 (DSB):
+*        Initial version with documentation taken from Fortran SLA
+*        Adapted with permission from the Fortran SLALIB library.
+*     {enter_further_changes_here}
+
+*  Copyright:
+*     Copyright (C) 1996 Rutherford Appleton Laboratory
+*     Copyright (C) 2012 Science and Technology Facilities Council.
+*     All Rights Reserved.
+
+*  Licence:
+*     This program is free software: you can redistribute it and/or
+*     modify it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
+*
+*     You should have received a copy of the GNU Lesser General
+*     License along with this program.  If not, see
+*     <http://www.gnu.org/licenses/>.
+
+*  Bugs:
+*     {note_any_bugs_here}
+*-
+*/
+
+#include "pal.h"
+#include "palmac.h"
+#include "pal1sofa.h"
+
+void palEcmat( double date, double rmat[3][3] ) {
+
+/* Mean obliquity (the angle between the ecliptic and mean equator of
+   date). */
+   double eps0 = eraObl06( PAL__MJD0, date );
+
+/* Matrix */
+   palDeuler( "X", eps0, 0.0, 0.0, rmat );
+
+}