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<b>let </b><font color="Maroon">N</font> be    <a href="subset_1.html#M1">Element</a> of  <a href="numbers.html#K5">NAT</a> ;<br/>

<b>assume </b><a NAME="E1:6"/>
<font color="Maroon">N</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0
 ;<br/>

<b>then consider </b><font color="Maroon">L</font> being   <a href="nat_1.html#NM1">Nat</a><b> such that </b><br/><a NAME="E3:6"/><i><font color="Green">E22</font></i>: 
<font color="Maroon">N</font> <a href="hidden.html#R1">=</a> <font color="Maroon">L</font> <a href="xcmplx_0.html#K2">+</a> 1
 <b>by </b><i><a class="ref" href="nat_1.html#T22">NAT_1:22</a></i>;<br/>
<b>reconsider </b><font color="Maroon">L</font> = <font color="Maroon">L</font> as    <a href="subset_1.html#M1">Element</a> of  <a href="numbers.html#K5">NAT</a>  <b>by </b><i><a class="ref" href="ordinal1.html#D13">ORDINAL1:def 13</a></i>;<br/>
<a NAME="E5:6"/>
<span class="p1">(<span class="default">6 <a href="nat_1.html#K2">*</a> <font color="Maroon">L</font></span>)</span> <a href="nat_1.html#K1">+</a> 2 <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0
 
<b>by </b><i><a class="ref" href="nat_1.html#T23">NAT_1:23</a></i>;<br/>
<b>hence </b><a NAME="E6:6"/>
<span class="p1">(<span class="default">6 <a href="nat_1.html#K2">*</a> <font color="Maroon">N</font></span>)</span> <a href="xcmplx_0.html#K6">-</a> 4 <a href="xxreal_0.html#NR4" target="_self">&gt;</a> 0
 <b>by </b><i>, <a class="ref" href="nat_1.html#T19">NAT_1:19</a></i>;<br/>


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