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<b>let </b><font color="Maroon" title="c1">T</font> be   <a href="helly.html#NM1" title="HELLY:NM.1">_Tree</a>;<br/><b>let </b><font color="Maroon" title="c2">P</font> be   <a href="glib_001.html#NM5" title="GLIB_001:NM.5">Path</a> of <font color="Maroon" title="c1">T</font>;<br/>



<b>assume </b><a NAME="E1:28"/>
( not <font color="Maroon" title="c2">P</font> is <a href="glib_001.html#V3" title="GLIB_001:attr.3">trivial</a> &amp; <font color="Maroon" title="c2">P</font> is <a href="glib_001.html#V1" title="GLIB_001:attr.1">closed</a> )
 ;<br/>

<a NAME="E2:28"/><b>then </b>
<font color="Maroon" title="c2">P</font> is <a href="glib_001.html#V8" title="GLIB_001:attr.8">Cycle-like</a>
 
<b>by </b><i><a class="ref" href="glib_001.html#D31" title="GLIB_001:def.31">GLIB_001:def 31</a></i>;<br/>
<b>hence </b><a NAME="E3:28"/>
contradiction
 <b>by </b><i><a class="ref" href="glib_002.html#D2" title="GLIB_002:def.2">GLIB_002:def 2</a></i>;<br/>


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