added ref to vars()
diff --git a/Doc/ref/ref4.tex b/Doc/ref/ref4.tex
index 2f2e1c8..151b0ae 100644
--- a/Doc/ref/ref4.tex
+++ b/Doc/ref/ref4.tex
@@ -119,6 +119,14 @@
\end{description}
+The built-in function \verb@vars()@ returns a dictionary representing
+the current local name space. The effect of modifications to this
+dictionary on the name space are undefined.%
+\footnote{The current implementation returns the dictionary actually
+used to implement the name space, {\em except} for functions, where
+the optimizer may cause the local name space to be implemented
+differently.}
+
\section{Exceptions}
Exceptions are a means of breaking out of the normal flow of control