diff --git a/Doc/lib/libtime.tex b/Doc/lib/libtime.tex
index 7e83f4e..3106542 100644
--- a/Doc/lib/libtime.tex
+++ b/Doc/lib/libtime.tex
@@ -2,8 +2,7 @@
 
 \bimodindex{time}
 This module provides various time-related functions.
-It is always available.  (On some systems, not all functions may
-exist; e.g. the ``milli'' variants can't always be implemented.)
+It is always available.
 
 An explanation of some terminology and conventions is in order.
 
@@ -55,6 +54,13 @@
 \end{funcdesc}
 
 
+\begin{funcdesc}{clock}{}
+Return the current CPU time as a floating point number expressed in
+seconds.  The precision depends on that of the C function by the same
+name.
+\end{funcdesc}
+
+
 \begin{funcdesc}{ctime}{secs}
 Convert a time expressed in seconds since the epoch to a string
 representing local time.  \code{ctime(t)} is equivalent to
@@ -78,18 +84,6 @@
 to 1 when DST applies to the given time.
 \end{funcdesc}
 
-\begin{funcdesc}{millisleep}{msecs}
-Suspend execution for the given number of milliseconds.  (Obsolete,
-you can now use use \code{sleep} with a floating point argument.)
-\end{funcdesc}
-
-\begin{funcdesc}{millitimer}{}
-Return the number of milliseconds of real time elapsed since some
-point in the past that is fixed per execution of the python
-interpreter (but may change in each following run).  The return value
-may be negative, and it may wrap around.
-\end{funcdesc}
-
 \begin{funcdesc}{mktime}{tuple}
 This is the inverse function of \code{localtime}.  Its argument is the
 full 9-tuple (since the dst flag is needed).  It returns an integer.
@@ -104,8 +98,7 @@
 Return the time as a floating point number expressed in seconds since
 the epoch, in UTC.  Note that even though the time is always returned
 as a floating point number, not all systems provide time with a better
-precision than 1 second.  An alternative for measuring precise
-intervals is \code{millitimer}.
+precision than 1 second.
 \end{funcdesc}
 
 \begin{datadesc}{timezone}
diff --git a/Doc/libtime.tex b/Doc/libtime.tex
index 7e83f4e..3106542 100644
--- a/Doc/libtime.tex
+++ b/Doc/libtime.tex
@@ -2,8 +2,7 @@
 
 \bimodindex{time}
 This module provides various time-related functions.
-It is always available.  (On some systems, not all functions may
-exist; e.g. the ``milli'' variants can't always be implemented.)
+It is always available.
 
 An explanation of some terminology and conventions is in order.
 
@@ -55,6 +54,13 @@
 \end{funcdesc}
 
 
+\begin{funcdesc}{clock}{}
+Return the current CPU time as a floating point number expressed in
+seconds.  The precision depends on that of the C function by the same
+name.
+\end{funcdesc}
+
+
 \begin{funcdesc}{ctime}{secs}
 Convert a time expressed in seconds since the epoch to a string
 representing local time.  \code{ctime(t)} is equivalent to
@@ -78,18 +84,6 @@
 to 1 when DST applies to the given time.
 \end{funcdesc}
 
-\begin{funcdesc}{millisleep}{msecs}
-Suspend execution for the given number of milliseconds.  (Obsolete,
-you can now use use \code{sleep} with a floating point argument.)
-\end{funcdesc}
-
-\begin{funcdesc}{millitimer}{}
-Return the number of milliseconds of real time elapsed since some
-point in the past that is fixed per execution of the python
-interpreter (but may change in each following run).  The return value
-may be negative, and it may wrap around.
-\end{funcdesc}
-
 \begin{funcdesc}{mktime}{tuple}
 This is the inverse function of \code{localtime}.  Its argument is the
 full 9-tuple (since the dst flag is needed).  It returns an integer.
@@ -104,8 +98,7 @@
 Return the time as a floating point number expressed in seconds since
 the epoch, in UTC.  Note that even though the time is always returned
 as a floating point number, not all systems provide time with a better
-precision than 1 second.  An alternative for measuring precise
-intervals is \code{millitimer}.
+precision than 1 second.
 \end{funcdesc}
 
 \begin{datadesc}{timezone}
diff --git a/Doc/ref/ref6.tex b/Doc/ref/ref6.tex
index b1d4572..53e6c40 100644
--- a/Doc/ref/ref6.tex
+++ b/Doc/ref/ref6.tex
@@ -190,11 +190,25 @@
 
 \end{itemize}
 	
-(In the original implementation, the syntax for targets is taken
+(In the current implementation, the syntax for targets is taken
 to be the same as for expressions, and invalid syntax is rejected
 during the code generation phase, causing less detailed error
 messages.)
 
+WARNING: Although the definition of assignment implies that overlaps
+between the left-hand side and the right-hand side are `safe' (e.g.
+\verb@a, b = b, a@ swaps two variables), overlaps within the
+collection of assigned-to variables are not safe!  For instance, the
+following program prints \code@[0, 2]@:
+
+\begin{verbatim}
+x = [0, 1]
+i = 0
+i, x[i] = 1, 2
+print x
+\end{verbatim}
+
+
 \section{The {\tt pass} statement}
 \stindex{pass}
 
diff --git a/Doc/ref6.tex b/Doc/ref6.tex
index b1d4572..53e6c40 100644
--- a/Doc/ref6.tex
+++ b/Doc/ref6.tex
@@ -190,11 +190,25 @@
 
 \end{itemize}
 	
-(In the original implementation, the syntax for targets is taken
+(In the current implementation, the syntax for targets is taken
 to be the same as for expressions, and invalid syntax is rejected
 during the code generation phase, causing less detailed error
 messages.)
 
+WARNING: Although the definition of assignment implies that overlaps
+between the left-hand side and the right-hand side are `safe' (e.g.
+\verb@a, b = b, a@ swaps two variables), overlaps within the
+collection of assigned-to variables are not safe!  For instance, the
+following program prints \code@[0, 2]@:
+
+\begin{verbatim}
+x = [0, 1]
+i = 0
+i, x[i] = 1, 2
+print x
+\end{verbatim}
+
+
 \section{The {\tt pass} statement}
 \stindex{pass}