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<b>let </b><font color="Maroon">X</font> be    <a href="hidden.html#M1">set</a> ;<br/><b>let </b><font color="Maroon">EqR1</font> be   <a href="eqrel_1.html#NM2">Equivalence_Relation</a> of <font color="Maroon">X</font>;<br/><b>let </b><font color="Maroon">EqR2</font> be   <a href="eqrel_1.html#NM2">Equivalence_Relation</a> of <font color="Maroon">X</font>;<br/>





<a NAME="E1:19"/><i><font color="Green">E38</font></i>: 
<font color="Maroon">EqR1</font> <a href="hidden.html#R1">=</a> <font color="Maroon">EqR1</font> <a href="eqrel_1.html#K3" target="_self">\/</a> <span class="p1">(<span class="default"><font color="Maroon">EqR1</font> <a href="eqrel_1.html#K4" target="_self">/\</a> <font color="Maroon">EqR2</font></span>)</span>
 
<b>by </b><i><a class="ref" href="xboole_1.html#T22">XBOOLE_1:22</a></i>;<br/>
<a NAME="E2:19"/>
for <font color="Olive">EqR</font> being  <a href="eqrel_1.html#NM2">Equivalence_Relation</a> of <font color="Maroon">X</font>  st <font color="Maroon">EqR1</font> <a href="eqrel_1.html#K3" target="_self">\/</a> <span class="p1">(<span class="default"><font color="Maroon">EqR1</font> <a href="eqrel_1.html#K4" target="_self">/\</a> <font color="Maroon">EqR2</font></span>)</span> <a href="tarski.html#R1">c=</a> <font color="Olive">EqR</font> holds <br/><font color="Maroon">EqR1</font> <a href="tarski.html#R1">c=</a> <font color="Olive">EqR</font>
 
<b>by </b><i><a class="ref" href="xboole_1.html#T22">XBOOLE_1:22</a></i>;<br/>
<b>hence </b><a NAME="E3:19"/>
<font color="Maroon">EqR1</font> <a href="eqrel_1.html#K5" target="_self">"\/"</a> <span class="p1">(<span class="default"><font color="Maroon">EqR1</font> <a href="eqrel_1.html#K4" target="_self">/\</a> <font color="Maroon">EqR2</font></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">EqR1</font>
 <b>by </b><i>, </i>;<br/>


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