Does someone know this "|" operator?
<p>I found the following algorithm:</p>

<p><a href="https://i.stack.imgur.com/ch2Uy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ch2Uy.png" alt="enter image description here"></a></p>

<p>Does someone recognize what is "|" ? </p>