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<b>let </b><font color="Maroon">G</font> be   <a href="graph_1.html#NM1">Graph</a>;<br/><b>let </b><font color="Maroon">v</font> be    <a href="subset_1.html#M1">Element</a> of the <a href="graph_1.html#U1">Vertices</a> of <font color="Maroon">G</font>;<br/>



<b>set </b><font color="Maroon">p</font> = <span class="p1"><a href="binarith.html#K11">&lt;*</a><span class="default"><font color="Maroon">v</font></span><a href="binarith.html#K11">*&gt;</a></span>;<br/>
<b>set </b><font color="Maroon">ec</font> =  <a href="xboole_0.html#K1">{}</a> ;<br/>
<i><font color="Green">E30</font></i>:  <a href="finseq_1.html#K3">len</a> <span class="p1"><a href="binarith.html#K11">&lt;*</a><span class="default"><font color="Maroon">v</font></span><a href="binarith.html#K11">*&gt;</a></span> = 
0 <a href="nat_1.html#K1">+</a> 1
<b>by </b><i><a class="ref" href="finseq_1.html#T56">FINSEQ_1:56</a></i>
<br/>.= 
<span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <a href="xboole_0.html#K1">{}</a> </span>)</span> <a href="nat_1.html#K1">+</a> 1
<b>by </b><i><a class="ref" href="finseq_1.html#T25">FINSEQ_1:25</a></i>
;<br/>
<a NAME="E2:65"/>
for <font color="Olive">n</font> being   <a href="subset_1.html#M1">Element</a> of  <a href="numbers.html#K5">NAT</a>   st 1 <a href="xxreal_0.html#R1">&lt;=</a> <font color="Olive">n</font> &amp; <font color="Olive">n</font> <a href="xxreal_0.html#R1">&lt;=</a>  <a href="finseq_1.html#K3">len</a> <a href="xboole_0.html#K1">{}</a>  holds <br/><a href="xboole_0.html#K1">{}</a>  <a href="funct_1.html#K1">.</a> <font color="Olive">n</font> <a href="graph_1.html#R2">joins</a> <span class="p1"><a href="binarith.html#K11">&lt;*</a><span class="default"><font color="Maroon">v</font></span><a href="binarith.html#K11">*&gt;</a></span> <a href="finseq_4.html#K4">/.</a> <font color="Olive">n</font>,<span class="p1"><a href="binarith.html#K11">&lt;*</a><span class="default"><font color="Maroon">v</font></span><a href="binarith.html#K11">*&gt;</a></span> <a href="finseq_4.html#K4">/.</a> <span class="p1">(<span class="default"><font color="Olive">n</font> <a href="nat_1.html#K1">+</a> 1</span>)</span>
 
<b>by </b><i><a class="ref" href="finseq_1.html#T25">FINSEQ_1:25</a></i>;<br/>
<b>hence </b><a NAME="E3:65"/>
<span class="p1"><a href="binarith.html#K11">&lt;*</a><span class="default"><font color="Maroon">v</font></span><a href="binarith.html#K11">*&gt;</a></span> <a href="graph_2.html#R1" target="_self">is_vertex_seq_of</a>  <a href="xboole_0.html#K1">{}</a> 
 <b>by </b><i>, <a class="ref" href="graph_2.html#T3" target="_self">Th3</a></i>;<br/>


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