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<b>let </b><font color="Maroon">c<sub>1</sub></font>, <font color="Maroon">c<sub>2</sub></font> be   <a href="subset_1.html#NM2">Subset</a> of <a href="hilbert1.html#K1" target="_self">HP-WFF</a> ;<br/>



<b>assume </b><b>that </b><br/><a NAME="E1:25"/><i><font color="Green">E18</font></i>: 
<font color="Maroon">c<sub>1</sub></font> is <a href="hilbert1.html#V6" target="_self">Hilbert_theory</a>
 <b>and </b><br/><a NAME="E2:25"/><i><font color="Green">E19</font></i>: 
<font color="Maroon">c<sub>2</sub></font> <a href="tarski.html#R1">c=</a> <font color="Maroon">c<sub>1</sub></font>
 ;<br/>

<b>let </b><font color="Maroon">c<sub>3</sub></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>thus </b><a NAME="E3:25"/>
(  not <font color="Maroon">c<sub>3</sub></font> <a href="hidden.html#R2">in</a>  <a href="hilbert1.html#K5" target="_self">CnPos</a> <font color="Maroon">c<sub>2</sub></font> or <font color="Maroon">c<sub>3</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>1</sub></font> )
 <b>by </b><i><a class="txt" href="hilbert1.html#E1:25"><i><font color="Green">E18</font></i></a>, <a class="txt" href="hilbert1.html#E2:25"><i><font color="Green">E19</font></i></a>, <a class="ref" href="hilbert1.html#D11" target="_self">Def11</a></i>;<br/>


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