Index: trunk/doc/pslib/psLibADD.tex
===================================================================
--- trunk/doc/pslib/psLibADD.tex	(revision 4514)
+++ trunk/doc/pslib/psLibADD.tex	(revision 4515)
@@ -1,3 +1,3 @@
-%%% $Id: psLibADD.tex,v 1.79 2005-07-08 03:59:17 price Exp $
+%%% $Id: psLibADD.tex,v 1.80 2005-07-08 04:00:45 price Exp $
 \documentclass[panstarrs]{panstarrs}
 
@@ -1528,5 +1528,6 @@
 where $\phi$ is the longitude and $\theta$ is the latitude.  Note that
 in this case, we neglect the scalar component of the quaternion --- it
-should be zero.
+should be zero --- and that we implicitly assume that the quaternion
+is normalised to unity.
 
 \subsubsection{Quaternion for a rotation}