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<b>let </b><font color="Maroon" title="c2">X</font> be    <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a> ;<br/>

<b>assume </b><a NAME="E1:36"/><i><font color="Green" title="E19">A1</font></i>: 
not <font color="Maroon" title="c2">X</font> is <a href="finset_1.html#V1" title="FINSET_1:attr.1">finite</a>
 ;<br/>

<b>assume </b><a NAME="E2:36"/>
<font color="Maroon" title="c2">X</font> is <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a>
 ;<br/>

<b>then reconsider </b><font color="Maroon" title="c3">X</font> = <font color="Maroon" title="c2">X</font> as  <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a>  <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a>  ;<br/>
<a NAME="E4:36"/>
<font color="Maroon" title="c3">X</font> is <a href="finset_1.html#V1" title="FINSET_1:attr.1">finite</a>
 
;<br/>
<b>hence </b><a NAME="E5:36"/>
contradiction
 <b>by </b><i><a class="txt" href="sfmastr1.html#E1:36"><i><font color="Green" title="E19">A1</font></i></a></i>;<br/>


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