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<div><span class="kw">theorem </span><a NAME="T31"><span class="comment"><font color="firebrick">:: NORMFORM:31</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">A</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a>  holds   <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  <a href="tarski.html#R2" title="TARSKI:pred.2">in</a>  <a href="normform.html#K8" title="NORMFORM:func.8">Normal_forms_on</a> <font color="Olive" title="b1">A</font> <span class="kw">by</span> <span class="lab"><a class="txt" href="normform.html#E42"><span class="lab"><font color="Green" title="E21">Lm4</font></span></a></span>;<br/></div></div>
