ff(w(x),x)</em> When <code>infudu</code> is unable to find
an antiderivative, it returns false.
</p>
<table><tr><td>&nbsp;</td><td><pre class="example">(%i1) intfudu(cos(x^2) * x,x);
(%o1) sin(x^2)/2

(%i3) intfudu(x * sqrt(1+x^2),x);
(%o3) (x^2+1)^(3/2)/3

(%i4) intfudu(x * sqrt(1 + x^4),x);
(%o4) false
</pre></td></tr></table>

<p>For the last example, the derivative divides rule fails, so
<code>intfudu</code> returns false. 
</p>
<p>A hashed array <code>intable</code> contains the antiderivative data. To