c</p><ul>

<p><li>The &lsquo;by&rsquo; argument in a &lsquo;for&rsquo;
loop can now be negative if it is additive. For the
multiplicative case, it must be greater than zero. </li></p></ul>

<p>eqn</p><ul>

<p><li>The following keywords aren&rsquo;t new but
haven&rsquo;t been documented previously:</p>

<p style="margin-left:3%; margin-top: 1em"><b>undef
NAME</b> (to undefine a macro) <b><br>
copy &quot;FILE&quot;</b> (a synonym for
&lsquo;include&rsquo;) <b><br>
space n</b> (to modify the vertical spacing b