diff --git a/Doc/lib/lib.tex b/Doc/lib/lib.tex
index 88ceffa..900cfac 100644
--- a/Doc/lib/lib.tex
+++ b/Doc/lib/lib.tex
@@ -2,14 +2,7 @@
 
 \title{Python Library Reference}
 
-\author{
-	Guido van Rossum \\
-	Dept. CST, CWI, P.O. Box 94079 \\
-	1090 GB Amsterdam, The Netherlands \\
-	E-mail: {\tt guido@cwi.nl}
-}
-
-\date{14 July 1994 \\ Release 1.0.3} % XXX update before release!
+\input{boilerplate}
 
 \makeindex			% tell \index to actually write the .idx file
 
@@ -20,6 +13,8 @@
 
 \maketitle
 
+\input{copyright}
+
 \begin{abstract}
 
 \noindent
diff --git a/Doc/lib/libsys.tex b/Doc/lib/libsys.tex
index cd2c646..e16fbd5 100644
--- a/Doc/lib/libsys.tex
+++ b/Doc/lib/libsys.tex
@@ -20,6 +20,15 @@
   modules.)
 \end{datadesc}
 
+\begin{datadesc}{check_interval}
+When this variable is set to an integer value, it determines how often
+the interpreter checks for periodic things such as thread switches and
+signal handlers.  The default is 10, meaning the check is performed
+every 10 Python virtual instructions.  Setting this to a large value
+may increase performance for programs using threads.  Setting it to a
+value <= 0 checks every virtual instruction, maximizing responsiveness
+as well as overhead.
+
 \begin{datadesc}{exc_type}
 \dataline{exc_value}
 \dataline{exc_traceback}