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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E37">Th57</font></span>: <a NAME="T57"><span class="comment"><font color="firebrick">:: CARD_3:57</font></span><br/></a><div class="add"> <a href="card_3.html#K8" title="CARD_3:func.8">sproduct</a> <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</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>
