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<b>let </b><font color="Maroon">X1</font> be    <a href="hidden.html#M1">set</a> , <font color="Maroon">X2</font> be    <a href="hidden.html#M1">set</a> ;<br/>

<b>assume </b><a NAME="E1:93_1_1"/><i><font color="Green">E26</font></i>: 
( ( for <font color="Olive">x</font> being   <a href="hidden.html#M1">set</a>  holds <br/> ( <font color="Olive">x</font> <a href="hidden.html#R2">in</a> <font color="Maroon">X1</font> iff  ex <font color="Olive">f</font> being <a href="cohsp_1.html#V9" target="_self">U-stable</a> <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">C1</font>,<font color="Maroon">C2</font> st <font color="Olive">x</font> <a href="hidden.html#R1">=</a>  <a href="cohsp_1.html#K8" target="_self">Trace</a> <font color="Olive">f</font> ) ) &amp; ( for <font color="Olive">x</font> being   <a href="hidden.html#M1">set</a>  holds <br/> ( <font color="Olive">x</font> <a href="hidden.html#R2">in</a> <font color="Maroon">X2</font> iff  ex <font color="Olive">f</font> being <a href="cohsp_1.html#V9" target="_self">U-stable</a> <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">C1</font>,<font color="Maroon">C2</font> st <font color="Olive">x</font> <a href="hidden.html#R1">=</a>  <a href="cohsp_1.html#K8" target="_self">Trace</a> <font color="Olive">f</font> ) ) &amp; not <font color="Maroon">X1</font> <a href="hidden.html#R1">=</a> <font color="Maroon">X2</font> )
 ;<br/>

<b>then consider </b><font color="Maroon">x</font> being    <a href="hidden.html#M1">set</a> <b> such that </b><br/><a NAME="E3:93_1_1"/><i><font color="Green">E27</font></i>: 
( ( <font color="Maroon">x</font> <a href="hidden.html#R2">in</a> <font color="Maroon">X1</font> &amp; not <font color="Maroon">x</font> <a href="hidden.html#R2">in</a> <font color="Maroon">X2</font> ) or ( <font color="Maroon">x</font> <a href="hidden.html#R2">in</a> <font color="Maroon">X2</font> &amp; not <font color="Maroon">x</font> <a href="hidden.html#R2">in</a> <font color="Maroon">X1</font> ) )
 <b>by </b><i><a class="ref" href="tarski.html#T2">TARSKI:2</a></i>;<br/>
<a NAME="E4:93_1_1"/>
( <font color="Maroon">x</font> <a href="hidden.html#R2">in</a> <font color="Maroon">X2</font> iff for <font color="Olive">f</font> being <a href="cohsp_1.html#V9" target="_self">U-stable</a> <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">C1</font>,<font color="Maroon">C2</font>  holds not <font color="Maroon">x</font> <a href="hidden.html#R1">=</a>  <a href="cohsp_1.html#K8" target="_self">Trace</a> <font color="Olive">f</font> )
 
<b>by </b><i><a class="ref" href="cohsp_1.html#T6" target="_self">Th6</a>, </i>;<br/>
<b>hence </b><a NAME="E5:93_1_1"/>
contradiction
 <b>by </b><i><a class="ref" href="cohsp_1.html#T6" target="_self">Th6</a></i>;<br/>


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