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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="hidden.html#M1">set</a> ;<br/>



<b>set </b><font color="Maroon">c<sub>3</sub></font> = <span class="p1">{<span class="default"> <span class="p2">(<span class="default"><a href="coh_sp.html#K15" target="_self">Toler</a> <font color="Olive">b<sub>1</sub></font></span>)</span> where B is   <a href="subset_1.html#NM2">Subset</a> of <font color="Maroon">c<sub>2</sub></font> : verum </span>}</span> ;<br/>
<b>assume </b><a NAME="E1:53"/>
<font color="Maroon">c<sub>1</sub></font> <a href="tarski.html#R1">c=</a> <font color="Maroon">c<sub>2</sub></font>
 ;<br/>

<a NAME="E2:53"/><b>then </b>
(  <a href="partfun1.html#K6">id</a> <font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#R2">in</a>  <a href="coh_sp.html#K15" target="_self">Toler</a> <font color="Maroon">c<sub>1</sub></font> &amp;  <a href="coh_sp.html#K15" target="_self">Toler</a> <font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#R2">in</a> <span class="p1">{<span class="default"> <span class="p2">(<span class="default"><a href="coh_sp.html#K15" target="_self">Toler</a> <font color="Olive">b<sub>1</sub></font></span>)</span> where B is   <a href="subset_1.html#NM2">Subset</a> of <font color="Maroon">c<sub>2</sub></font> : verum </span>}</span>  )
 
<b>by </b><i><a class="ref" href="coh_sp.html#D19" target="_self">Def19</a></i>;<br/>
<a NAME="E3:53"/><b>then </b>
 <a href="partfun1.html#K6">id</a> <font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#R2">in</a>  <a href="tarski.html#K3">union</a> <span class="p1">{<span class="default"> <span class="p2">(<span class="default"><a href="coh_sp.html#K15" target="_self">Toler</a> <font color="Olive">b<sub>1</sub></font></span>)</span> where B is   <a href="subset_1.html#NM2">Subset</a> of <font color="Maroon">c<sub>2</sub></font> : verum </span>}</span> 
 
<b>by </b><i><a class="ref" href="tarski.html#D4">TARSKI:def 4</a></i>;<br/>
<b>hence </b><a NAME="E4:53"/>
 <a href="partfun1.html#K6">id</a> <font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#R2">in</a>  <a href="coh_sp.html#K16" target="_self">Toler_on_subsets</a> <font color="Maroon">c<sub>2</sub></font>
 ;<br/>


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