<p>It’s just part of the rule. If you ended up having 6 sign changes, you could have 6, 4, 2 or 0.</p>
<p>But it really is entirely useless.</p>
<p>It’s just part of the rule. If you ended up having 6 sign changes, you could have 6, 4, 2 or 0.</p>
<p>But it really is entirely useless.</p>