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

<b>let </b><font color="Maroon">G</font> be  <a href="group_1.html#V1">strict</a> <a href="group_1.html#NM1">Group</a>;<br/><b>let </b><font color="Maroon">b</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">G</font>;<br/>



<a NAME="E1:13"/><i><font color="Green">E34</font></i>: 
( <font color="Maroon">b</font> <a href="group_1.html#NR2" target="_self">is_of_order_0</a>  implies for <font color="Olive">n</font> being  <a href="int_1.html#NM1">Integer</a>  st <font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <font color="Olive">n</font> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font> holds <br/><font color="Olive">n</font> <a href="hidden.html#R1">=</a> 0 )
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="13_1"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:13_1"/><i><font color="Green">E40</font></i>: 
<font color="Maroon">b</font> <a href="group_1.html#NR2" target="_self">is_of_order_0</a> 
 ;<br/>

<a NAME="E2:13_1"/><b>then </b><i><font color="Green">E41</font></i>: 
for <font color="Olive">m</font> being   <a href="subset_1.html#M1">Element</a> of  <a href="numbers.html#K5">NAT</a>   st <font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <font color="Olive">m</font> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font> holds <br/><font color="Olive">m</font> <a href="hidden.html#R1">=</a> 0
 
<b>by </b><i><a class="ref" href="group_1.html#D11">GROUP_1:def 11</a></i>;<br/>
<a NAME="E3:13_1"/><i><font color="Green">E42</font></i>: 
for <font color="Olive">m</font> being   <a href="subset_1.html#M1">Element</a> of  <a href="numbers.html#K5">NAT</a>   st <font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <span class="p1">(<span class="default"><a href="xcmplx_0.html#K4">-</a> <font color="Olive">m</font></span>)</span> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font> holds <br/><font color="Olive">m</font> <a href="hidden.html#R1">=</a> 0
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="13_1_1"><b>proof </b></a><div class="add">

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

<b>assume </b><a NAME="E1:13_1_1"/><i><font color="Green">E47</font></i>: 
<font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <span class="p1">(<span class="default"><a href="xcmplx_0.html#K4">-</a> <font color="Maroon">m</font></span>)</span> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font>
 ;<br/>

<a NAME="E2:13_1_1"/><i><font color="Green">E48</font></i>: 
<font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <span class="p1">(<span class="default"><a href="xcmplx_0.html#K4">-</a> <font color="Maroon">m</font></span>)</span> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <font color="Maroon">m</font></span>)</span> <a href="group_1.html#K3">"</a> 
 
<b>by </b><i><a class="ref" href="group_1.html#T71">GROUP_1:71</a></i>;<br/>
<a NAME="E3:13_1_1"/><i><font color="Green">E51</font></i>: 
<span class="p1">(<span class="default"><font color="Maroon">b</font> <a href="group_1.html#K3">"</a> </span>)</span> <a href="group_1.html#K6">|^</a> <font color="Maroon">m</font> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font>
 
<b>by </b><i>, , <a class="ref" href="group_1.html#T72">GROUP_1:72</a></i>;<br/>
<a NAME="E4:13_1_1"/>
<font color="Maroon">b</font> <a href="group_1.html#K3">"</a>  <a href="group_1.html#NR2" target="_self">is_of_order_0</a> 
 
<b>by </b><i>, </i>;<br/>
<b>hence </b><a NAME="E5:13_1_1"/>
<font color="Maroon">m</font> <a href="hidden.html#R1">=</a> 0
 <b>by </b><i>, <a class="ref" href="group_1.html#D11">GROUP_1:def 11</a></i>;<br/>


</div><b>end;</b></div>
<a NAME="E4:13_1"/>
for <font color="Olive">n</font> being  <a href="int_1.html#NM1">Integer</a>  st <font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <font color="Olive">n</font> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font> holds <br/><font color="Olive">n</font> <a href="hidden.html#R1">=</a> 0
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="13_1_2"><b>proof </b></a><div class="add">

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

<b>assume </b><a NAME="E1:13_1_2"/><i><font color="Green">E63</font></i>: 
<font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <font color="Maroon">n</font> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font>
 ;<br/>

<b>consider </b><font color="Maroon">k</font> being    <a href="subset_1.html#M1">Element</a> of  <a href="numbers.html#K5">NAT</a> <b> such that </b><br/><a NAME="E3:13_1_2"/><i><font color="Green">E64</font></i>: 
( <font color="Maroon">n</font> <a href="hidden.html#R1">=</a> <font color="Maroon">k</font> or <font color="Maroon">n</font> <a href="hidden.html#R1">=</a>  <a href="xcmplx_0.html#K4">-</a> <font color="Maroon">k</font> )
 <b>by </b><i><a class="ref" href="int_1.html#T8">INT_1:8</a></i>;<br/>
<div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="13_1_2_1"><b>per </b></a><a class="txt" onclick="hs(this)" href="javascript:()"><b>cases </b></a><span class="hide"><a NAME="E1:13_1_2_1"/>
( <font color="Maroon">n</font> <a href="hidden.html#R1">=</a> <font color="Maroon">k</font> or <font color="Maroon">n</font> <a href="hidden.html#R1">=</a>  <a href="xcmplx_0.html#K4">-</a> <font color="Maroon">k</font> )
 </span><b>by </b><i/>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="13_1_2_1_1"><b>suppose </b></a><a NAME="E1:13_1_2_1_1"/>
<font color="Maroon">n</font> <a href="hidden.html#R1">=</a> <font color="Maroon">k</font>
 ;<br/><div class="add"><b>hence </b><a NAME="E2:13_1_2_1_1"/>
<font color="Maroon">n</font> <a href="hidden.html#R1">=</a> 0
 <b>by </b><i>, </i>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="13_1_2_1_2"><b>suppose </b></a><a NAME="E1:13_1_2_1_2"/><i><font color="Green">E65</font></i>: 
<font color="Maroon">n</font> <a href="hidden.html#R1">=</a>  <a href="xcmplx_0.html#K4">-</a> <font color="Maroon">k</font>
 ;<br/><div class="add"><a NAME="E2:13_1_2_1_2"/><b>then </b>
<font color="Maroon">k</font> <a href="hidden.html#R1">=</a> 0
 <b>by </b><i>, </i>;<br/><b>hence </b><a NAME="E3:13_1_2_1_2"/>
<font color="Maroon">n</font> <a href="hidden.html#R1">=</a> 0
 <b>by </b><i/>;<br/></div><b>end;</b></div></div><b>end;</b></div>

</div><b>end;</b></div>
<b>hence </b><a NAME="E5:13_1"/>
for <font color="Olive">n</font> being  <a href="int_1.html#NM1">Integer</a>  st <font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <font color="Olive">n</font> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font> holds <br/><font color="Olive">n</font> <a href="hidden.html#R1">=</a> 0
 ;<br/>


</div><b>end;</b></div>
<a NAME="E2:13"/>
( ( for <font color="Olive">n</font> being  <a href="int_1.html#NM1">Integer</a>  st <font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <font color="Olive">n</font> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font> holds <br/><font color="Olive">n</font> <a href="hidden.html#R1">=</a> 0 ) implies <font color="Maroon">b</font> <a href="group_1.html#NR2" target="_self">is_of_order_0</a>  )
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="13_2"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:13_2"/>
for <font color="Olive">n</font> being  <a href="int_1.html#NM1">Integer</a>  st <font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <font color="Olive">n</font> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font> holds <br/><font color="Olive">n</font> <a href="hidden.html#R1">=</a> 0
 ;<br/>

<a NAME="E2:13_2"/><b>then </b>
for <font color="Olive">n</font> being  <a href="nat_1.html#NM1">Nat</a>  st <font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <font color="Olive">n</font> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font> holds <br/><font color="Olive">n</font> <a href="hidden.html#R1">=</a> 0
 
;<br/>
<b>hence </b><a NAME="E3:13_2"/>
<font color="Maroon">b</font> <a href="group_1.html#NR2" target="_self">is_of_order_0</a> 
 <b>by </b><i><a class="ref" href="group_1.html#D11">GROUP_1:def 11</a></i>;<br/>


</div><b>end;</b></div>
<b>hence </b><a NAME="E3:13"/>
( <font color="Maroon">b</font> <a href="group_1.html#NR2" target="_self">is_of_order_0</a>  iff for <font color="Olive">n</font> being  <a href="int_1.html#NM1">Integer</a>  st <font color="Maroon">b</font> <a href="group_1.html#K6">|^</a> <font color="Olive">n</font> <a href="hidden.html#R1">=</a>  <a href="group_1.html#K2">1.</a> <font color="Maroon">G</font> holds <br/><font color="Olive">n</font> <a href="hidden.html#R1">=</a> 0 )
 <b>by </b><i/>;<br/>


</div>
