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<b>let </b><font color="Maroon" title="c1">a</font> be    <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a> ;<br/>

<a NAME="E1:15_1"/>
<font color="Maroon">P<sub>1</sub></font>[<font color="Maroon" title="c1">a</font>,<font color="Maroon" title="c1">a</font>]
 
<b>by </b><i><a class="txt" href="schems_1.html#E1:15"><i><font color="Green" title="E1">A1</font></i></a></i>;<br/>
<b>hence </b><a NAME="E2:15_1"/>
 ex <font color="Olive" title="b1">b</font> being   <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a>  st <font color="Maroon">P<sub>1</sub></font>[<font color="Maroon" title="c1">a</font>,<font color="Olive" title="b1">b</font>]
 ;<br/>


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