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<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="11_1_1_1"><b>now </b></a><div class="add"><b>let </b><font color="Maroon">i</font> be    <a href="hidden.html#M1">set</a> ;<br/><b>assume </b><a NAME="E1:11_1_1_1"/>
<font color="Maroon">i</font> <a href="hidden.html#R2">in</a> the <a href="struct_0.html#U1">carrier</a> of <font color="Maroon">S</font>
 ;<br/><b>then reconsider </b><font color="Maroon">s</font> = <font color="Maroon">i</font> as   <a href="msualg_1.html#NM1">SortSymbol</a> of <font color="Maroon">S</font> ;<br/><a NAME="E3:11_1_1_1"/>
<span class="p1">(<span class="default"><a href="msualg_2.html#K2" target="_self">Constants</a> <font color="Maroon">U0</font></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">s</font> <a href="hidden.html#R1">=</a>  <a href="msualg_2.html#K1" target="_self">Constants</a> <font color="Maroon">U0</font>,<font color="Maroon">s</font>
 <b>by </b><i/>;<br/><b>hence </b><a NAME="E4:11_1_1_1"/>
not <span class="p1">(<span class="default"><a href="msualg_2.html#K2" target="_self">Constants</a> <font color="Maroon">U0</font></span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">i</font> is <a href="xboole_0.html#V1">empty</a>
 ;<br/></div><b>end;</b></div>
<b>hence </b><a NAME="E2:11_1_1"/>
 <a href="msualg_2.html#K2" target="_self">Constants</a> <font color="Maroon">U0</font> is <a href="relat_1.html#V2">non-empty</a>
 <b>by </b><i><a class="ref" href="pboole.html#D16">PBOOLE:def 16</a></i>;<br/>


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