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<b>let </b><font color="Maroon">c<sub>1</sub></font> be   <a href="int_1.html#NM1">Integer</a>;<br/>

<i><font color="Green">E18</font></i>: <font color="Maroon">c<sub>1</sub></font> <a href="int_2.html#K3">gcd</a> 0 = 
<span class="p1">(<span class="default"><a href="prepower.html#K1">abs</a> <font color="Maroon">c<sub>1</sub></font></span>)</span> <a href="nat_1.html#K8">hcf</a> <span class="p1">(<span class="default"><a href="prepower.html#K1">abs</a> 0</span>)</span>
<b>by </b><i><a class="ref" href="int_2.html#D3">INT_2:def 3</a></i>
<br/>.= 
<span class="p1">(<span class="default"><a href="prepower.html#K1">abs</a> <font color="Maroon">c<sub>1</sub></font></span>)</span> <a href="nat_1.html#K8">hcf</a> 0
<b>by </b><i><a class="ref" href="absvalue.html#T7">ABSVALUE:7</a></i>
<br/>.= 
 <a href="prepower.html#K1">abs</a> <font color="Maroon">c<sub>1</sub></font>
<b>by </b><i><a class="ref" href="newton.html#T65">NEWTON:65</a></i>
;<br/>
<font color="Maroon">c<sub>1</sub></font> <a href="int_2.html#K3">gcd</a> 1 = 
<span class="p1">(<span class="default"><a href="prepower.html#K1">abs</a> <font color="Maroon">c<sub>1</sub></font></span>)</span> <a href="nat_1.html#K8">hcf</a> <span class="p1">(<span class="default"><a href="prepower.html#K1">abs</a> 1</span>)</span>
<b>by </b><i><a class="ref" href="int_2.html#D3">INT_2:def 3</a></i>
<br/>.= 
<span class="p1">(<span class="default"><a href="prepower.html#K1">abs</a> <font color="Maroon">c<sub>1</sub></font></span>)</span> <a href="nat_1.html#K8">hcf</a> 1
<b>by </b><i><a class="ref" href="absvalue.html#D1">ABSVALUE:def 1</a></i>
<br/>.= 
1
<b>by </b><i><a class="ref" href="newton.html#T64">NEWTON:64</a></i>
;<br/>
<b>hence </b><a NAME="E3:17"/>
( 0 <a href="int_2.html#K3">gcd</a> <font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#R1">=</a>  <a href="prepower.html#K1">abs</a> <font color="Maroon">c<sub>1</sub></font> &amp; 1 <a href="int_2.html#K3">gcd</a> <font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#R1">=</a> 1 )
 <b>by </b><i><a class="txt" href="wsierp_1.html#E1:17"><i><font color="Green">E18</font></i></a></i>;<br/>


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