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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E47">Th25</font></span>: <a NAME="T25"><span class="comment"><font color="firebrick">:: NUMBER09:25</font></span><br/></a><div class="add"> <a href="gr_cy_3.html#K1" title="GR_CY_3:func.1">Mersenne</a> 19 is  <a href="int_2.html#V1" title="INT_2:attr.1">prime</a> </div></div>
