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

<a NAME="E1:48_1_1"/>
 <a href="heyting3.html#K2" target="_self">PFArt</a> 1,<font color="Maroon">k</font> <a href="hidden.html#R2">in</a>  <a href="heyting3.html#K4" target="_self">PFBrt</a> 1,<font color="Maroon">k</font>
 
<b>by </b><i/>;<br/>
<b>hence </b><a NAME="E2:48_1_1"/>
not  <a href="heyting3.html#K4" target="_self">PFBrt</a> 1,<font color="Maroon">k</font> is <a href="xboole_0.html#V1">empty</a>
 ;<br/>


</div>
