<?xml version="1.0"?>
<div class="add">

 <a href="finseq_1.html#K3">len</a> <span class="p1">(<span class="default"><a href="uproots.html#K1">canFS</a> <a href="xboole_0.html#K1">{}</a> </span>)</span> = 
 <a href="card_1.html#K4">card</a> <a href="xboole_0.html#K1">{}</a> 
<b>by </b><i><a class="ref" href="uproots.html#D1">UPROOTS:def 1</a></i>
<br/>.= 
 <a href="xboole_0.html#K1">{}</a> 

;<br/>
<b>hence </b><a NAME="E2:18_1_1"/>
 <a href="uproots.html#K1">canFS</a> <a href="xboole_0.html#K1">{}</a>  is <a href="xboole_0.html#V1">empty</a>
 <b>by </b><i><a class="ref" href="finseq_1.html#T25">FINSEQ_1:25</a></i>;<br/>


</div>
