ode> to attempt to determine an
antiderivative.
</p>
<p>Each function <code>f</code> in <code>extra_integration_methods</code> should have
the form <code>f(integrand, variable)</code>. The function <code>f</code> may
either return <code>false</code> to indicate failure, or it may return an
expression involving an integration noun form. The integration methods
are tried from the first to the last member of
<code>extra_integration_methods</code>; when no method returns an expression
that does not involve an i