<?xml version="1.0"?>
<div class="add">

<b>let </b><font color="Maroon">c<sub>1</sub></font> be  <a href="ordinal1.html#V7">natural</a>  <a href="ordinal1.html#NM1" target="_self">number</a> ;<br/>

<b>reconsider </b><font color="Maroon">c<sub>2</sub></font> = <font color="Maroon">c<sub>1</sub></font> <a href="xcmplx_0.html#K6">-</a> 0 as   <a href="nat_1.html#NM1">Nat</a> <b>by </b><i><a class="ref" href="ordinal1.html#D13">ORDINAL1:def 13</a></i>;<br/>
<a NAME="E2:32"/><i><font color="Green">E18</font></i>: 
<font color="Maroon">c<sub>1</sub></font> <a href="newton.html#K6" target="_self">!</a>  <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0
 
<b>by </b><i><a class="ref" href="newton.html#T23" target="_self">Th23</a></i>;<br/>
<a NAME="E3:32"/>
<font color="Maroon">c<sub>2</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>1</sub></font>
 
;<br/>
<b>then </b><font color="Maroon">c<sub>1</sub></font> <a href="newton.html#K8" target="_self">choose</a> 0 = 
<span class="p1">(<span class="default"><font color="Maroon">c<sub>1</sub></font> <a href="newton.html#K6" target="_self">!</a> </span>)</span> <a href="xcmplx_0.html#K7">/</a> <span class="p1">(<span class="default">1 <a href="xcmplx_0.html#K3">*</a> <span class="p2">(<span class="default"><font color="Maroon">c<sub>1</sub></font> <a href="newton.html#K6" target="_self">!</a> </span>)</span></span>)</span>
<b>by </b><i><a class="ref" href="newton.html#D3" target="_self">Def3</a>, <a class="ref" href="newton.html#T18" target="_self">Th18</a></i>
<br/>.= 
1
<b>by </b><i><a class="txt" href="newton.html#E2:32"><i><font color="Green">E18</font></i></a>, <a class="ref" href="xcmplx_1.html#T60">XCMPLX_1:60</a></i>
;<br/>
<b>hence </b><a NAME="E5:32"/>
<font color="Maroon">c<sub>1</sub></font> <a href="newton.html#K8" target="_self">choose</a> 0 <a href="hidden.html#R1">=</a> 1
 ;<br/>


</div>
