I think you misunderstood his question. I have the same problem.<p>How do you get from this line:<p><pre><code>    (A1Y and B2Y and B3Y) or (A1Y and A2Y and B3Y) 
</code></pre>
to this<p><pre><code>    (A1Y and B2Y) or (A2Y and B3Y)
</code></pre>
BrandonSmithJ just did some replacement to make it easier to read. Maybe he shouldn&#x27;t have used the same letters to avoid confusion.<p>Let&#x27;s write it differently: Why are these terms equivalent?<p><pre><code>   (u &amp;&amp; v &amp;&amp; w) || (u &amp;&amp; x &amp;&amp; w)
   (u &amp;&amp; v)  || (x &amp;&amp; w)</code></pre>