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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E16">Th17</font></span>: <a NAME="T17"><span class="comment"><font color="firebrick">:: HEYTING3:17</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">n</font>, <font color="Olive" title="b2">k</font> being    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of  <a href="numbers.html#NK1" title="NUMBERS:NK.1">NAT</a>  holds   <a href="heyting3.html#K3" title="HEYTING3:func.3">PFCrt</a> (<font color="Olive" title="b1">n</font>,<font color="Olive" title="b2">k</font>) <a href="xboole_0.html#R2" title="XBOOLE_0:pred.2">c&lt;</a>  <a href="heyting3.html#K3" title="HEYTING3:func.3">PFCrt</a> (<span class="p1">(<span class="default"><font color="Olive" title="b1">n</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span>,<font color="Olive" title="b2">k</font>)</div></div>
