that <code>A</code> implies <code>B</code></li>
<li>then <code>B</code> is true.</li>
</ul>
</blockquote>
<p>Logicians like to write this as an <em>inference rule</em>, as follows:</p>
<pre><code>  A     A ==&gt; B
==================
       B
</code></pre>
<p>And in general they call this rule the <em>modus monens</em>.</p>
<p>(but the lambda-calculus expression is more explicit, e.g. about the meaning of the “horizontal bar” and also the quantification of <code>A</code> and <code>B</code>).</p>
<p>This