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<div>:: <span class="kw">deftheorem </span>   defines <a href="nat_5.html#K5" title="NAT_5:func.5">sigma</a> <a onclick="hs(this)" href="javascript:()">NAT_5:def 4 : <br/></a><span> for <font color="Olive" title="b1">n</font> being   <a href="ordinal1.html#V7" title="ORDINAL1:attr.7">natural</a>   <a href="ordinal1.html#NM1" title="ORDINAL1:NM.1">Number</a>  holds   <a href="nat_5.html#K5" title="NAT_5:func.5">sigma</a> <font color="Olive" title="b1">n</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="nat_5.html#K3" title="NAT_5:func.3">sigma</a> (1,<font color="Olive" title="b1">n</font>);<br/></span></div>
