Added "module search path" to the index.
diff --git a/Doc/libsys.tex b/Doc/libsys.tex
index 8d36dc0..e4cd875 100644
--- a/Doc/libsys.tex
+++ b/Doc/libsys.tex
@@ -129,6 +129,7 @@
 \end{datadesc}
 
 \begin{datadesc}{path}
+\indexiii{module}{search}{path}
   A list of strings that specifies the search path for modules.
   Initialized from the environment variable \code{PYTHONPATH}, or an
   installation-dependent default.