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<b>let </b><font color="Maroon">x</font> be    <a href="hidden.html#M1">set</a> , <font color="Maroon">y</font> be    <a href="hidden.html#M1">set</a> ; <i><font color="Red">:: according to </font></i><a class="ref" href="taxonom2.html#D5" target="_self">TAXONOM2:def 5</a><br/>

<b>assume </b><a NAME="E1:19"/>
( <font color="Maroon">x</font> <a href="hidden.html#R2">in</a>  <a href="xboole_0.html#K1">{}</a>  &amp; <font color="Maroon">y</font> <a href="hidden.html#R2">in</a>  <a href="xboole_0.html#K1">{}</a>  )
 ;<br/>

<b>hence </b><a NAME="E2:19"/>
(  not <font color="Maroon">x</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">y</font> or <font color="Maroon">x</font> <a href="xboole_0.html#R1">misses</a> <font color="Maroon">y</font> )
 ;<br/>


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