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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>, <font color="Maroon">c<sub>3</sub></font>, <font color="Maroon">c<sub>4</sub></font> be    <a href="pboole.html#M1" target="_self">ManySortedSet</a> of <font color="Maroon">c<sub>1</sub></font>;<br/>







<b>assume </b><b>that </b><br/><a NAME="E1:126"/><i><font color="Green">E70</font></i>: 
<font color="Maroon">c<sub>2</sub></font> <a href="pboole.html#R7" target="_self">[=</a> <font color="Maroon">c<sub>3</sub></font>
 <b>and </b><br/><a NAME="E2:126"/><i><font color="Green">E71</font></i>: 
<font color="Maroon">c<sub>3</sub></font> <a href="pboole.html#R7" target="_self">[=</a> <font color="Maroon">c<sub>4</sub></font>
 ;<br/>

<b>let </b><font color="Maroon">c<sub>5</sub></font> be    <a href="pboole.html#M1" target="_self">ManySortedSet</a> of <font color="Maroon">c<sub>1</sub></font>; <i><font color="Red">:: according to </font></i><a class="ref" href="pboole.html#D14" target="_self">PBOOLE:def 14</a><br/>

<b>assume </b><a NAME="E3:126"/>
<font color="Maroon">c<sub>5</sub></font> <a href="pboole.html#R1" target="_self">in</a> <font color="Maroon">c<sub>2</sub></font>
 ;<br/>

<a NAME="E4:126"/><b>then </b>
<font color="Maroon">c<sub>5</sub></font> <a href="pboole.html#R1" target="_self">in</a> <font color="Maroon">c<sub>3</sub></font>
 
<b>by </b><i><a class="txt" href="pboole.html#E1:126"><i><font color="Green">E70</font></i></a>, <a class="ref" href="pboole.html#D14" target="_self">Def14</a></i>;<br/>
<b>hence </b><a NAME="E5:126"/>
<font color="Maroon">c<sub>5</sub></font> <a href="pboole.html#R1" target="_self">in</a> <font color="Maroon">c<sub>4</sub></font>
 <b>by </b><i><a class="txt" href="pboole.html#E2:126"><i><font color="Green">E71</font></i></a>, <a class="ref" href="pboole.html#D14" target="_self">Def14</a></i>;<br/>


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