op ><tt>newline</tt> </td><td valign=top ><tt>(rnrs io simple (6))</tt> </td></tr>
<tr><td valign=top ><tt>null-environment</tt> </td><td valign=top ><tt>(rnrs r5rs (6))</tt> </td></tr>
<tr><td valign=top ><tt>open-input-file</tt> </td><td valign=top ><tt>(rnrs io simple (6))</tt> </td></tr>
<tr><td valign=top ><tt>open-output-file</tt> </td><td valign=top ><tt>(rnrs io simple (6))</tt> </td></tr>
<tr><td valign=top ><tt>peek-char</tt> </td><td valign=top ><tt>(rnrs io simple (6))</tt> </td></tr>
<tr><td va