new file mode 100644
--- /dev/null
+++ b/liboctave/lo-cieee.c
@@ -0,0 +1,84 @@
+/*
+
+Copyright (C) 2002 John W. Eaton
+
+This file is part of Octave.
+
+Octave 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 2, or (at your option) any
+later version.
+
+Octave 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 Octave; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <float.h>
+#include <math.h>
+
+#if defined (HAVE_FLOATINGPOINT_H)
+#include <floatingpoint.h>
+#endif
+
+#if defined (HAVE_IEEEFP_H)
+#include <ieeefp.h>
+#endif
+
+#if defined (HAVE_NAN_H)
+#if defined (SCO)
+#define _IEEE 1
+#endif
+#include <nan.h>
+#if defined (SCO)
+#undef _IEEE
+#endif
+#endif
+
+#include "lo-ieee.h"
+
+#if defined (SCO)
+
+int
+isnan (double x)
+{
+  return (IsNANorINF (x) && NaN (x) && ! IsINF (x)) ? 1 : 0;
+}
+
+int
+isinf (double x)
+{
+  return (IsNANorINF (x) && IsINF (x)) ? 1 : 0;
+}
+
+#endif
+
+int
+lo_ieee_is_NA (double x)
+{
+  lo_ieee_double t;
+  t.value = x;
+  return (isnan (x) && t.word[lo_ieee_lw] == LO_IEEE_NA_LW) ? 1 : 0;
+}
+
+int
+lo_ieee_is_NaN_or_NA (double x)
+{
+  return isnan (x);
+}
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; End: ***
+*/