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diff --git a/src/slalib/prenut.f b/src/slalib/prenut.f
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+      SUBROUTINE sla_PRENUT (EPOCH, DATE, RMATPN)
+*+
+*     - - - - - - -
+*      P R E N U T
+*     - - - - - - -
+*
+*  Form the matrix of precession and nutation (IAU1976/FK5)
+*  (double precision)
+*
+*  Given:
+*     EPOCH   dp         Julian Epoch for mean coordinates
+*     DATE    dp         Modified Julian Date (JD-2400000.5)
+*                        for true coordinates
+*
+*  Returned:
+*     RMATPN  dp(3,3)    combined precession/nutation matrix
+*
+*  Called:  sla_PREC, sla_EPJ, sla_NUT, sla_DMXM
+*
+*  Notes:
+*
+*  1)  The epoch and date are TDB (loosely ET).
+*
+*  2)  The matrix is in the sense   V(true)  =  RMATPN * V(mean)
+*
+*  P.T.Wallace   Starlink   April 1987
+*
+*  Copyright (C) 1995 Rutherford Appleton Laboratory
+*-
+
+      IMPLICIT NONE
+
+      DOUBLE PRECISION EPOCH,DATE,RMATPN(3,3)
+
+      DOUBLE PRECISION RMATP(3,3),RMATN(3,3),sla_EPJ
+
+
+
+*  Precession
+      CALL sla_PREC(EPOCH,sla_EPJ(DATE),RMATP)
+
+*  Nutation
+      CALL sla_NUT(DATE,RMATN)
+
+*  Combine the matrices:  PN = N x P
+      CALL sla_DMXM(RMATN,RMATP,RMATPN)
+
+      END