de>inner_prod</code> computes the inner product of the vector
expressions. <code>prec_inner_prod</code> computes the double
precision inner product of the vector expressions<code>.</code></p>
<h4>Definition</h4>
<p>Defined in the header vector_expression.hpp.</p>
<h4>Type requirements</h4>
<ul>
<li><code>E1</code> is a model of <a href=
"#vector_expression">Vector Expression</a> .</li>
<li><code>E2</code> is a model of <a href=
"#vector_expression">Vector Expression</a> .</li>
</ul>
<h4>Preconditions</h4>
<