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<b>let </b><font color="Maroon">c<sub>1</sub></font> be    <a href="hidden.html#M1">set</a> ;<br/><b>let </b><font color="Maroon">c<sub>2</sub></font> be    <a href="subset_1.html#M1">Element</a> of <span class="p1"><a href="zfmisc_1.html#K2">[:</a><span class="default"><span class="p2">(<span class="default"><a href="finsub_1.html#K5">Fin</a> <font color="Maroon">c<sub>1</sub></font></span>)</span>,<span class="p2">(<span class="default"><a href="finsub_1.html#K5">Fin</a> <font color="Maroon">c<sub>1</sub></font></span>)</span></span><a href="zfmisc_1.html#K2">:]</a></span>;<br/>



<a NAME="E1:26"/>
<span class="p1"><a href="domain_1.html#K1">[</a><span class="default"><span class="p2">(<span class="default"><a href="setwiseo.html#K1">{}.</a> <font color="Maroon">c<sub>1</sub></font></span>)</span>,<span class="p2">(<span class="default"><a href="setwiseo.html#K1">{}.</a> <font color="Maroon">c<sub>1</sub></font></span>)</span></span><a href="domain_1.html#K1">]</a></span> <a href="binop_1.html#R3">is_a_unity_wrt</a>  <a href="normform.html#K5" target="_self">FinPairUnion</a> <font color="Maroon">c<sub>1</sub></font>
 
<b>by </b><i><a class="ref" href="normform.html#T36" target="_self">Th36</a></i>;<br/>
<a NAME="E2:26"/><b>then </b>
 <a href="binop_1.html#K3">the_unity_wrt</a> <span class="p1">(<span class="default"><a href="normform.html#K5" target="_self">FinPairUnion</a> <font color="Maroon">c<sub>1</sub></font></span>)</span> <a href="hidden.html#R1">=</a> <span class="p1"><a href="tarski.html#K4">[</a><span class="default"><a href="xboole_0.html#K1">{}</a> ,<a href="xboole_0.html#K1">{}</a> </span><a href="tarski.html#K4">]</a></span>
 
<b>by </b><i><a class="ref" href="binop_1.html#D8">BINOP_1:def 8</a></i>;<br/>
<a NAME="E3:26"/><b>then </b>
( <span class="p1">(<span class="default"><a href="binop_1.html#K3">the_unity_wrt</a> <span class="p2">(<span class="default"><a href="normform.html#K5" target="_self">FinPairUnion</a> <font color="Maroon">c<sub>1</sub></font></span>)</span></span>)</span> <a href="domain_1.html#K2">`1</a>  <a href="hidden.html#R1">=</a>  <a href="xboole_0.html#K1">{}</a>  &amp; <span class="p1">(<span class="default"><a href="binop_1.html#K3">the_unity_wrt</a> <span class="p2">(<span class="default"><a href="normform.html#K5" target="_self">FinPairUnion</a> <font color="Maroon">c<sub>1</sub></font></span>)</span></span>)</span> <a href="domain_1.html#K3">`2</a>  <a href="hidden.html#R1">=</a>  <a href="xboole_0.html#K1">{}</a>  )
 
<b>by </b><i><a class="ref" href="mcart_1.html#T7">MCART_1:7</a></i>;<br/>
<b>hence </b><a NAME="E4:26"/>
( <span class="p1">(<span class="default"><a href="binop_1.html#K3">the_unity_wrt</a> <span class="p2">(<span class="default"><a href="normform.html#K5" target="_self">FinPairUnion</a> <font color="Maroon">c<sub>1</sub></font></span>)</span></span>)</span> <a href="domain_1.html#K2">`1</a>  <a href="tarski.html#R1">c=</a> <font color="Maroon">c<sub>2</sub></font> <a href="domain_1.html#K2">`1</a>  &amp; <span class="p1">(<span class="default"><a href="binop_1.html#K3">the_unity_wrt</a> <span class="p2">(<span class="default"><a href="normform.html#K5" target="_self">FinPairUnion</a> <font color="Maroon">c<sub>1</sub></font></span>)</span></span>)</span> <a href="domain_1.html#K3">`2</a>  <a href="tarski.html#R1">c=</a> <font color="Maroon">c<sub>2</sub></font> <a href="domain_1.html#K3">`2</a>  )
 <b>by </b><i><a class="ref" href="xboole_1.html#T2">XBOOLE_1:2</a></i>; <i><font color="Red">:: according to </font></i><a class="ref" href="normform.html#D1" target="_self">NORMFORM:def 1</a><br/>


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