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<div><span class="kw">theorem </span><a NAME="T7"><span class="comment"><font color="firebrick">:: QC_LANG1:7</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">A</font> being    <a href="qc_lang1.html#M1" title="QC_LANG1:mode.1">QC-alphabet</a>  holds   <a href="qc_lang1.html#K9" title="QC_LANG1:func.9">QC-WFF</a> <font color="Olive" title="b1">A</font> is <font color="Olive" title="b1">A</font> <a href="qc_lang1.html#V1" title="QC_LANG1:attr.1">-closed</a>  <span class="kw">by</span> <span class="lab"><a class="ref" href="qc_lang1.html#D11" target="_self" onmouseover="rs('qc_lang1/D11')" onmouseout="rh()">Def11</a></span>;<br/></div></div>
