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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E22">Th28</font></span>: <a NAME="T29"><span class="comment"><font color="firebrick">:: TREES_1:29</font></span><br/></a><div class="add"> <a href="trees_1.html#K2" title="TREES_1:func.2">elementary_tree</a> <a href="numbers.html#K5" title="NUMBERS:func.5">0</a> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1"><a href="tarski.html#K1" title="TARSKI:func.1">{</a><span class="default"><a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a></span><a href="tarski.html#K1" title="TARSKI:func.1">}</a></span></div></div>
