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<div><span class="kw">theorem </span><a NAME="T121"><span class="comment"><font color="firebrick">:: PBOOLE:121</font></span><br/></a><div class="add"> <a href="pboole.html#K1" title="PBOOLE:func.1">EmptyMS</a> <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> <a href="pboole.html#R1" title="PBOOLE:pred.1">in</a>  <a href="pboole.html#K1" title="PBOOLE:func.1">EmptyMS</a> <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> ;<br/></div></div>
