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<b>let </b><font color="Maroon">t</font> be  <a href="finset_1.html#V1">finite</a> <a href="trees_1.html#NM1">Tree</a>;<br/><b>let </b><font color="Maroon">p</font> be    <a href="trees_1.html#M1">Element</a> of <font color="Maroon">t</font>;<br/>



<a NAME="E1:33"/>
( <font color="Maroon">p</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="xboole_0.html#K1">{}</a>  implies  <a href="trees_1.html#K6">height</a> <font color="Maroon">t</font> <a href="xxreal_0.html#NR4" target="_self">&gt;</a>  <a href="trees_1.html#K6">height</a> <span class="p1">(<span class="default"><font color="Maroon">t</font> <a href="trees_1.html#K4">|</a> <font color="Maroon">p</font></span>)</span> )
 
<b>by </b><i><a class="ref" href="trees_1.html#T85">TREES_1:85</a></i>;<br/>
<b>hence </b><a NAME="E2:33"/>
( <font color="Maroon">t</font> <a href="hidden.html#R1">=</a> <font color="Maroon">t</font> <a href="trees_1.html#K4">|</a> <font color="Maroon">p</font> implies <font color="Maroon">p</font> <a href="hidden.html#R1">=</a>  <a href="xboole_0.html#K1">{}</a>  )
 ;<br/>


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