Work around the conversion of ">>" and "<<" to guillemets. Reported by Ping.

Doc/mac/using.tex

@@ -27,8 +27,8 @@ The interactive interpreter that you will see used in Python
 documentation is started by double-clicking the
 \program{PythonInterpreter} icon, which looks like a 16-ton weight
 falling. You should see the version information and the
-\samp{>>>~} prompt.  Use it exactly as described in the standard
-documentation.
+\samp{>\code{>}>~} prompt.  Use it exactly as described in the
+standard documentation.
 
 
 \section{How to run a Python script}