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<b>let </b><font color="Maroon" title="c1">I</font> be    <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a> ;<br/><b>let </b><font color="Maroon" title="c2">Y</font>, <font color="Maroon" title="c3">Z</font> be    <a href="pboole.html#M1" title="PBOOLE:mode.1">ManySortedSet</a> of <font color="Maroon" title="c1">I</font>;<br/><b>let </b><font color="Maroon" title="c4">X</font> be  <a href="relat_1.html#V2" title="RELAT_1:attr.2">V5</a>  <a href="pboole.html#M1" title="PBOOLE:mode.1">ManySortedSet</a> of <font color="Maroon" title="c1">I</font>;<br/>







<b>assume </b><a NAME="E1:144"/><i><font color="Green" title="E77">A1</font></i>: 
for <font color="Olive" title="b1">x</font> being   <a href="pboole.html#M1" title="PBOOLE:mode.1">ManySortedSet</a> of <font color="Maroon" title="c1">I</font> holds <br/> ( <font color="Olive" title="b1">x</font> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a> <font color="Maroon" title="c4">X</font> iff ( <font color="Olive" title="b1">x</font> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a> <font color="Maroon" title="c2">Y</font> &amp; <font color="Olive" title="b1">x</font> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a> <font color="Maroon" title="c3">Z</font> ) )
 ;<br/>

<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="144_1"><b>now </b></a><div class="add"><b>let </b><font color="Maroon" title="c5">x</font> be    <a href="pboole.html#M1" title="PBOOLE:mode.1">ManySortedSet</a> of <font color="Maroon" title="c1">I</font>;<br/><div><b>hereby </b>
<div class="add"><b>assume </b><a NAME="E1:144_1_1"/>
<font color="Maroon" title="c5">x</font> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a> <font color="Maroon" title="c4">X</font>
 ;<br/><a NAME="E2:144_1_1"/><b>then </b>
( <font color="Maroon" title="c5">x</font> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a> <font color="Maroon" title="c2">Y</font> &amp; <font color="Maroon" title="c5">x</font> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a> <font color="Maroon" title="c3">Z</font> )
 <b>by </b><i><a class="txt" href="pboole.html#E1:144"><i><font color="Green" title="E77">A1</font></i></a></i>;<br/><b>hence </b><a NAME="E3:144_1_1"/>
<font color="Maroon" title="c5">x</font> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a> <font color="Maroon" title="c2">Y</font> <a href="pboole.html#K3" title="PBOOLE:func.3">/\</a> <font color="Maroon" title="c3">Z</font>
 <b>by </b><i><a class="ref" href="pboole.html#T8" target="_self" title="PBOOLE:th.8">Th8</a></i>;<br/></div>
<b>end;</b></div><b>assume </b><a NAME="E2:144_1"/>
<font color="Maroon" title="c5">x</font> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a> <font color="Maroon" title="c2">Y</font> <a href="pboole.html#K3" title="PBOOLE:func.3">/\</a> <font color="Maroon" title="c3">Z</font>
 ;<br/><a NAME="E3:144_1"/><b>then </b>
( <font color="Maroon" title="c5">x</font> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a> <font color="Maroon" title="c2">Y</font> &amp; <font color="Maroon" title="c5">x</font> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a> <font color="Maroon" title="c3">Z</font> )
 <b>by </b><i><a class="ref" href="pboole.html#T8" target="_self" title="PBOOLE:th.8">Th8</a></i>;<br/><b>hence </b><a NAME="E4:144_1"/>
<font color="Maroon" title="c5">x</font> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a> <font color="Maroon" title="c4">X</font>
 <b>by </b><i><a class="txt" href="pboole.html#E1:144"><i><font color="Green" title="E77">A1</font></i></a></i>;<br/></div><b>end;</b></div>
<b>hence </b><a NAME="E3:144"/>
<font color="Maroon" title="c4">X</font> <a href="pboole.html#R6" title="PBOOLE:pred.6">=</a> <font color="Maroon" title="c2">Y</font> <a href="pboole.html#K3" title="PBOOLE:func.3">/\</a> <font color="Maroon" title="c3">Z</font>
 <b>by </b><i><a class="ref" href="pboole.html#T147" target="_self" title="PBOOLE:th.147">Th147</a></i>;<br/>


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