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<b>let </b><font color="Maroon">S1</font> be   <a href="osalg_1.html#NM3">OrderSortedSign</a>;<br/><b>let </b><font color="Maroon">U0</font> be  <a href="msualg_1.html#V5">non-empty</a> <a href="osalg_1.html#NM5">OSAlgebra</a> of <font color="Maroon">S1</font>;<br/><b>let </b><font color="Maroon">U1</font> be  <a href="msualg_1.html#V4">strict</a> <a href="osalg_2.html#NM3">OSSubAlgebra</a> of <font color="Maroon">U0</font>, <font color="Maroon">U2</font> be  <a href="msualg_1.html#V4">strict</a> <a href="osalg_2.html#NM3">OSSubAlgebra</a> of <font color="Maroon">U0</font>;<br/>





<b>reconsider </b><font color="Maroon">u12</font> = the <a href="msualg_1.html#U4">Sorts</a> of <span class="p1">(<span class="default"><font color="Maroon">U1</font> <a href="msualg_2.html#K11">/\</a> <font color="Maroon">U2</font></span>)</span>, <font color="Maroon">u2</font> = the <a href="msualg_1.html#U4">Sorts</a> of <font color="Maroon">U2</font> as   <a href="msualg_2.html#NM1">MSSubset</a> of <font color="Maroon">U0</font> <b>by </b><i><a class="ref" href="msualg_2.html#D10">MSUALG_2:def 10</a></i>;<br/>
<a NAME="E2:69"/><i><font color="Green">E25</font></i>: 
( <font color="Maroon">u12</font> is   <a href="osalg_1.html#NM4">OrderSortedSet</a> of <font color="Maroon">S1</font> &amp; <font color="Maroon">u2</font> is   <a href="osalg_1.html#NM4">OrderSortedSet</a> of <font color="Maroon">S1</font> )
 
<b>by </b><i><a class="ref" href="osalg_1.html#T17">OSALG_1:17</a></i>;<br/>
<b>then reconsider </b><font color="Maroon">u12</font> = <font color="Maroon">u12</font>, <font color="Maroon">u2</font> = <font color="Maroon">u2</font> as    <a href="osalg_2.html#M2" target="_self">OSSubset</a> of <font color="Maroon">U0</font> <b>by </b><i/>;<br/>
<a NAME="E4:69"/>
( <font color="Maroon">u12</font> <a href="pboole.html#R2">c=</a> the <a href="msualg_1.html#U4">Sorts</a> of <font color="Maroon">U0</font> &amp; <font color="Maroon">u2</font> <a href="pboole.html#R2">c=</a> the <a href="msualg_1.html#U4">Sorts</a> of <font color="Maroon">U0</font> )
 
<b>by </b><i><a class="ref" href="pboole.html#D23">PBOOLE:def 23</a></i>;<br/>
<a NAME="E5:69"/><b>then </b>
<font color="Maroon">u12</font> <a href="pboole.html#K2">\/</a> <font color="Maroon">u2</font> <a href="pboole.html#R2">c=</a> the <a href="msualg_1.html#U4">Sorts</a> of <font color="Maroon">U0</font>
 
<b>by </b><i><a class="ref" href="pboole.html#T18">PBOOLE:18</a></i>;<br/>
<b>then reconsider </b><font color="Maroon">A</font> = <font color="Maroon">u12</font> <a href="pboole.html#K2">\/</a> <font color="Maroon">u2</font> as   <a href="msualg_2.html#NM1">MSSubset</a> of <font color="Maroon">U0</font> <b>by </b><i><a class="ref" href="pboole.html#D23">PBOOLE:def 23</a></i>;<br/>
<a NAME="E7:69"/>
<font color="Maroon">A</font> is   <a href="osalg_1.html#NM4">OrderSortedSet</a> of <font color="Maroon">S1</font>
 
<b>by </b><i>, </i>;<br/>
<b>then reconsider </b><font color="Maroon">A</font> = <font color="Maroon">u12</font> <a href="pboole.html#K2">\/</a> <font color="Maroon">u2</font> as    <a href="osalg_2.html#M2" target="_self">OSSubset</a> of <font color="Maroon">U0</font> <b>by </b><i/>;<br/>
<a NAME="E9:69"/><i><font color="Green">E26</font></i>: 
<span class="p1">(<span class="default"><font color="Maroon">U1</font> <a href="msualg_2.html#K11">/\</a> <font color="Maroon">U2</font></span>)</span> <a href="osalg_2.html#K11" target="_self">"\/"_os</a> <font color="Maroon">U2</font> <a href="hidden.html#R1">=</a>  <a href="osalg_2.html#K10" target="_self">GenOSAlg</a> <font color="Maroon">A</font>
 
<b>by </b><i/>;<br/>
<a NAME="E10:69"/>
<font color="Maroon">u12</font> <a href="pboole.html#R6">=</a> the <a href="msualg_1.html#U4">Sorts</a> of <font color="Maroon">U1</font> <a href="pboole.html#K3">/\</a> the <a href="msualg_1.html#U4">Sorts</a> of <font color="Maroon">U2</font>
 
<b>by </b><i><a class="ref" href="msualg_2.html#D17">MSUALG_2:def 17</a></i>;<br/>
<a NAME="E11:69"/><b>then </b>
<font color="Maroon">u12</font> <a href="pboole.html#R2">c=</a> <font color="Maroon">u2</font>
 
<b>by </b><i><a class="ref" href="pboole.html#T17">PBOOLE:17</a></i>;<br/>
<a NAME="E12:69"/><b>then </b>
<font color="Maroon">A</font> <a href="pboole.html#R6">=</a> <font color="Maroon">u2</font>
 
<b>by </b><i><a class="ref" href="pboole.html#T24">PBOOLE:24</a></i>;<br/>
<b>hence </b><a NAME="E13:69"/>
<span class="p1">(<span class="default"><font color="Maroon">U1</font> <a href="msualg_2.html#K11">/\</a> <font color="Maroon">U2</font></span>)</span> <a href="osalg_2.html#K11" target="_self">"\/"_os</a> <font color="Maroon">U2</font> <a href="hidden.html#R1">=</a> <font color="Maroon">U2</font>
 <b>by </b><i>, </i>;<br/>


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