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<b>let </b><font color="Maroon">I</font> be    <a href="hidden.html#M1">set</a> ;<br/><b>let </b><font color="Maroon">M</font> be    <a href="pboole.html#M1">ManySortedSet</a> of <font color="Maroon">I</font>;<br/><b>let </b><font color="Maroon">SF</font> be   <a href="mssubfam.html#NM1">MSSubsetFamily</a> of <font color="Maroon">M</font>;<br/><b>let </b><font color="Maroon">SG</font> be   <a href="mssubfam.html#NM1">MSSubsetFamily</a> of <font color="Maroon">M</font>;<br/>







<a NAME="E1:58"/>
( <font color="Maroon">SF</font> <a href="pboole.html#K4">\</a> <font color="Maroon">SG</font> is   <a href="mssubfam.html#NM1">MSSubsetFamily</a> of <font color="Maroon">M</font> &amp; <font color="Maroon">SG</font> <a href="pboole.html#K4">\</a> <font color="Maroon">SF</font> is   <a href="mssubfam.html#NM1">MSSubsetFamily</a> of <font color="Maroon">M</font> )
 
<b>by </b><i/>;<br/>
<a NAME="E2:58"/><b>then </b>
<span class="p1">(<span class="default"><font color="Maroon">SF</font> <a href="pboole.html#K4">\</a> <font color="Maroon">SG</font></span>)</span> <a href="pboole.html#K2">\/</a> <span class="p1">(<span class="default"><font color="Maroon">SG</font> <a href="pboole.html#K4">\</a> <font color="Maroon">SF</font></span>)</span> is   <a href="mssubfam.html#NM1">MSSubsetFamily</a> of <font color="Maroon">M</font>
 
<b>by </b><i/>;<br/>
<b>hence </b><a NAME="E3:58"/>
<font color="Maroon">SF</font> <a href="pboole.html#K5">\+\</a> <font color="Maroon">SG</font> is   <a href="mssubfam.html#NM1">MSSubsetFamily</a> of <font color="Maroon">M</font>
 ;<br/>


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