op ><tt>(rnrs io simple (6))</tt> </td></tr>
<tr><td valign=top ><tt>close-output-port</tt> </td><td valign=top ><tt>(rnrs io simple (6))</tt> </td></tr>
<tr><td valign=top ><tt>current-input-port</tt> </td><td valign=top ><tt>(rnrs io simple (6))</tt> </td></tr>
<tr><td valign=top ><tt>current-output-port</tt> </td><td valign=top ><tt>(rnrs io simple (6))</tt> </td></tr>
<tr><td valign=top ><tt>display</tt> </td><td valign=top ><tt>(rnrs io simple (6))</tt> </td></tr>
<tr><td valign=top ><tt>do</tt> </td><