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<b>let </b><font color="Maroon">D</font> be  non <a href="xboole_0.html#V1">empty</a>  <a href="hidden.html#M1">set</a> ;<br/><b>let </b><font color="Maroon">f1</font> be    <a href="finseq_1.html#M2">FinSequence</a> of <font color="Maroon">D</font>;<br/><b>let </b><font color="Maroon">f2</font> be    <a href="finseq_1.html#M2">FinSequence</a> of <font color="Maroon">D</font>;<br/>





<b>assume </b><a NAME="E1:83"/>
<font color="Maroon">f1</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="xboole_0.html#K1">{}</a> 
 ;<br/>

<b>then consider </b><font color="Maroon">p</font> being    <a href="subset_1.html#M1">Element</a> of <font color="Maroon">D</font>, <font color="Maroon">df1</font> being    <a href="finseq_1.html#M2">FinSequence</a> of <font color="Maroon">D</font><b> such that </b><br/><a NAME="E3:83"/>
<font color="Maroon">p</font> <a href="hidden.html#R1">=</a> <font color="Maroon">f1</font> <a href="funct_1.html#K1">.</a> 1
 <b>and </b><br/><a NAME="E4:83"/><i><font color="Green">E30</font></i>: 
<font color="Maroon">f1</font> <a href="hidden.html#R1">=</a> <span class="p1"><a href="finseq_1.html#K12">&lt;*</a><span class="default"><font color="Maroon">p</font></span><a href="finseq_1.html#K12">*&gt;</a></span> <a href="finseq_1.html#K8">^</a> <font color="Maroon">df1</font>
 <b>by </b><i><a class="ref" href="finseq_3.html#T111">FINSEQ_3:111</a></i>;<br/>
<b>thus </b><span class="p1">(<span class="default"><font color="Maroon">f1</font> <a href="finseq_1.html#K8">^</a> <font color="Maroon">f2</font></span>)</span> <a href="rfinseq.html#K1">/^</a> 1 = 
<span class="p1">(<span class="default"><span class="p2"><a href="finseq_1.html#K12">&lt;*</a><span class="default"><font color="Maroon">p</font></span><a href="finseq_1.html#K12">*&gt;</a></span> <a href="finseq_1.html#K8">^</a> <span class="p2">(<span class="default"><font color="Maroon">df1</font> <a href="finseq_1.html#K8">^</a> <font color="Maroon">f2</font></span>)</span></span>)</span> <a href="rfinseq.html#K1">/^</a> 1
<b>by </b><i><a class="ref" href="finseq_6.html#T19" target="_self">Th19</a>, <a class="ref" href="finseq_1.html#T45">FINSEQ_1:45</a></i>
<br/>.= 
<font color="Maroon">df1</font> <a href="finseq_1.html#K8">^</a> <font color="Maroon">f2</font>
<b>by </b><i><a class="ref" href="finseq_6.html#T5" target="_self">Th5</a></i>
<br/>.= 
<span class="p1">(<span class="default"><font color="Maroon">f1</font> <a href="rfinseq.html#K1">/^</a> 1</span>)</span> <a href="finseq_1.html#K8">^</a> <font color="Maroon">f2</font>
<b>by </b><i><a class="ref" href="finseq_6.html#T19" target="_self">Th19</a>, <a class="ref" href="finseq_6.html#T5" target="_self">Th5</a></i>
;<br/>


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