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<b>let </b><font color="Maroon">V</font> be    <a href="hidden.html#M1">set</a> ;<br/><b>let </b><font color="Maroon">C</font> be  <a href="finset_1.html#V1">finite</a>  <a href="hidden.html#M1">set</a> ;<br/><b>let </b><font color="Maroon">A</font> be    <a href="subset_1.html#M1">Element</a> of  <a href="finsub_1.html#K5">Fin</a> <span class="p1">(<span class="default"><a href="partfun1.html#K4">PFuncs</a> <font color="Maroon">V</font>,<font color="Maroon">C</font></span>)</span>;<br/><b>let </b><font color="Maroon">a</font> be    <a href="hidden.html#M1">set</a> ; <i><font color="Red">:: according to </font></i><a class="ref" href="tarski.html#D3">TARSKI:def 3</a><br/>







<b>assume </b><a NAME="E1:14"/>
<font color="Maroon">a</font> <a href="hidden.html#R2">in</a>  <a href="heyting2.html#K1" target="_self">Involved</a> <font color="Maroon">A</font>
 ;<br/>

<b>then consider </b><font color="Maroon">f</font> being  <a href="finset_1.html#V1">finite</a> <a href="funct_1.html#NM1">Function</a><b> such that </b><br/><a NAME="E3:14"/><i><font color="Green">E21</font></i>: 
( <font color="Maroon">f</font> <a href="hidden.html#R2">in</a> <font color="Maroon">A</font> &amp; <font color="Maroon">a</font> <a href="hidden.html#R2">in</a>  <a href="relat_1.html#K1">dom</a> <font color="Maroon">f</font> )
 <b>by </b><i/>;<br/>
<a NAME="E4:14"/>
<font color="Maroon">A</font> <a href="tarski.html#R1">c=</a>  <a href="partfun1.html#K4">PFuncs</a> <font color="Maroon">V</font>,<font color="Maroon">C</font>
 
<b>by </b><i><a class="ref" href="finsub_1.html#D5">FINSUB_1:def 5</a></i>;<br/>
<b>then consider </b><font color="Maroon">f1</font> being   <a href="funct_1.html#NM1">Function</a><b> such that </b><br/><a NAME="E6:14"/><i><font color="Green">E24</font></i>: 
( <font color="Maroon">f</font> <a href="hidden.html#R1">=</a> <font color="Maroon">f1</font> &amp;  <a href="relat_1.html#K1">dom</a> <font color="Maroon">f1</font> <a href="tarski.html#R1">c=</a> <font color="Maroon">V</font> &amp;  <a href="relat_1.html#K2">rng</a> <font color="Maroon">f1</font> <a href="tarski.html#R1">c=</a> <font color="Maroon">C</font> )
 <b>by </b><i>, <a class="ref" href="partfun1.html#D5">PARTFUN1:def 5</a></i>;<br/>
<b>thus </b><a NAME="E7:14"/>
<font color="Maroon">a</font> <a href="hidden.html#R2">in</a> <font color="Maroon">V</font>
 <b>by </b><i>, </i>;<br/>


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