,
     and newline do not take port arguments.  current-input-port
     returns nil.</li>

<li> map and for-each only take two arguments. </li>

<li> number-&gt;string only takes one argument. </li>

<li> string-&gt;symbol will be slow with enough symbols. </li>

</ul>

<h2>Extensions</h2>

<p>These are not in R5RS.</p>

<ul>

<li> (display-stderr foo) is like display, but uses stderr. </li>

<li> (exit 37) makes the program exit with exit code 37. </li>

<li> (error foo bar baz) aborts the program and send