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<b>let </b><font color="Maroon" title="c1">S</font> be   <a href="osalg_1.html#NM3" title="OSALG_1:NM.3">OrderSortedSign</a>;<br/><b>let </b><font color="Maroon" title="c2">on</font> be   <a href="osalg_1.html#NM6" title="OSALG_1:NM.6">OperName</a> of <font color="Maroon" title="c1">S</font>;<br/><b>let </b><font color="Maroon" title="c3">op1</font> be   <a href="osalg_1.html#NM2" title="OSALG_1:NM.2">OperSymbol</a> of <font color="Maroon" title="c1">S</font>;<br/>





<div><b>hereby </b>
<div class="add"><b>assume </b><a NAME="E1:90_1"/>
<font color="Maroon" title="c3">op1</font> is    <a href="osalg_1.html#M1" title="OSALG_1:mode.1">Element</a> of <font color="Maroon" title="c2">on</font>
 ;<br/><b>then reconsider </b><font color="Maroon" title="c4">op</font> = <font color="Maroon" title="c3">op1</font> as    <a href="osalg_1.html#M1" title="OSALG_1:mode.1">Element</a> of <font color="Maroon" title="c2">on</font> ;<br/><b>consider </b><font color="Maroon" title="c5">op2</font> being    <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a> <b> such that </b><br/><a NAME="E4:90_1"/><i><font color="Green" title="E49">A1</font></i>: 
<font color="Maroon" title="c5">op2</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a> the <a href="msualg_1.html#U1" title="MSUALG_1:sel.1">OperSymbols</a> of <font color="Maroon" title="c1">S</font>
 <b>and </b><br/><a NAME="E5:90_1"/><i><font color="Green" title="E50">A2</font></i>: 
<font color="Maroon" title="c2">on</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="eqrel_1.html#K7" title="EQREL_1:func.7">Class</a> the <a href="osalg_1.html#U1" title="OSALG_1:sel.1">Overloading</a> of <font color="Maroon" title="c1">S</font>,<font color="Maroon" title="c5">op2</font>
 <b>by </b><i><a class="ref" href="eqrel_1.html#D5" title="EQREL_1:def.5">EQREL_1:def 5</a></i>;<br/><a NAME="E6:90_1"/>
 <a href="osalg_1.html#K10" title="OSALG_1:func.10">Name</a> <font color="Maroon" title="c4">op</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="eqrel_1.html#K7" title="EQREL_1:func.7">Class</a> the <a href="osalg_1.html#U1" title="OSALG_1:sel.1">Overloading</a> of <font color="Maroon" title="c1">S</font>,<font color="Maroon" title="c4">op</font>
 ;<br/><b>hence </b><a NAME="E7:90_1"/>
 <a href="osalg_1.html#K10" title="OSALG_1:func.10">Name</a> <font color="Maroon" title="c3">op1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">on</font>
 <b>by </b><i><a class="txt" href="osalg_1.html#E4:90_1"><i><font color="Green" title="E49">A1</font></i></a>, <a class="txt" href="osalg_1.html#E5:90_1"><i><font color="Green" title="E50">A2</font></i></a>, <a class="ref" href="eqrel_1.html#T31" title="EQREL_1:th.31">EQREL_1:31</a></i>;<br/></div>
<b>end;</b></div>

<b>assume </b><a NAME="E2:90"/>
 <a href="osalg_1.html#K10" title="OSALG_1:func.10">Name</a> <font color="Maroon" title="c3">op1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">on</font>
 ;<br/>

<a NAME="E3:90"/><b>then </b>
 <a href="eqrel_1.html#K7" title="EQREL_1:func.7">Class</a> the <a href="osalg_1.html#U1" title="OSALG_1:sel.1">Overloading</a> of <font color="Maroon" title="c1">S</font>,<font color="Maroon" title="c3">op1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">on</font>
 
;<br/>
<b>hence </b><a NAME="E4:90"/>
<font color="Maroon" title="c3">op1</font> is    <a href="osalg_1.html#M1" title="OSALG_1:mode.1">Element</a> of <font color="Maroon" title="c2">on</font>
 <b>by </b><i><a class="ref" href="eqrel_1.html#T28" title="EQREL_1:th.28">EQREL_1:28</a></i>;<br/>


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