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

<b>let </b><font color="Maroon">n</font> be   <a href="nat_1.html#NM1">Nat</a>;<br/>

<b>set </b><font color="Maroon">fm</font> =  <a href="real_3.html#K1" target="_self">modSeq</a> 0,<font color="Maroon">n</font>;<br/>
<b>set </b><font color="Maroon">fd</font> =  <a href="real_3.html#K2" target="_self">divSeq</a> 0,<font color="Maroon">n</font>;<br/>
<a NAME="E1:41"/><i><font color="Green">E31</font></i>: 
 <a href="relset_1.html#K4">dom</a> <span class="p1">(<span class="default"><a href="real_3.html#K1" target="_self">modSeq</a> 0,<font color="Maroon">n</font></span>)</span> <a href="hidden.html#R1">=</a>  <a href="numbers.html#K5">NAT</a> 
 
<b>by </b><i><a class="ref" href="funct_2.html#D1">FUNCT_2:def 1</a></i>;<br/>
<a NAME="E2:41"/>
for <font color="Olive">x</font> being   <a href="hidden.html#M1">set</a>   st <font color="Olive">x</font> <a href="hidden.html#R2">in</a>  <a href="relset_1.html#K4">dom</a> <span class="p1">(<span class="default"><a href="real_3.html#K1" target="_self">modSeq</a> 0,<font color="Maroon">n</font></span>)</span> holds <br/><span class="p1">(<span class="default"><a href="real_3.html#K1" target="_self">modSeq</a> 0,<font color="Maroon">n</font></span>)</span> <a href="seq_1.html#K2">.</a> <font color="Olive">x</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><a href="numbers.html#K5">NAT</a>  <a href="funcop_1.html#K2">--&gt;</a> 0</span>)</span> <a href="funct_1.html#K1">.</a> <font color="Olive">x</font>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="41_1"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">x</font> be    <a href="hidden.html#M1">set</a> ;<br/>

<b>assume </b><a NAME="E1:41_1"/>
<font color="Maroon">x</font> <a href="hidden.html#R2">in</a>  <a href="relset_1.html#K4">dom</a> <span class="p1">(<span class="default"><a href="real_3.html#K1" target="_self">modSeq</a> 0,<font color="Maroon">n</font></span>)</span>
 ;<br/>

<b>then reconsider </b><font color="Maroon">x</font> = <font color="Maroon">x</font> as    <a href="subset_1.html#M2">Element</a> of  <a href="numbers.html#K5">NAT</a>  ;<br/>
<b>defpred </b><font color="Maroon">S<sub>1</sub></font>[  <a href="nat_1.html#NM1">Nat</a>] <b>means </b><span class="p1">(<span class="default"><a href="real_3.html#K1" target="_self">modSeq</a> 0,<font color="Maroon">n</font></span>)</span> <a href="seq_1.html#K2">.</a> <font color="Maroon">a<sub>1</sub></font> <a href="hidden.html#R1">=</a> 0;<br/>
<a NAME="E3:41_1"/><i><font color="Green">E32</font></i>: 
<font color="Maroon">S<sub>1</sub></font>[0]
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="41_1_1"><b>proof </b></a><div class="add">

<b>thus </b><span class="p1">(<span class="default"><a href="real_3.html#K1" target="_self">modSeq</a> 0,<font color="Maroon">n</font></span>)</span> <a href="funct_2.html#K3">.</a> 0 = 
0 <a href="nat_1.html#K6">mod</a> <font color="Maroon">n</font>
<b>by </b><i/>
<br/>.= 
0

;<br/>


</div><b>end;</b></div>
<a NAME="E4:41_1"/><i><font color="Green">E33</font></i>: 
for <font color="Olive">x</font> being  <a href="nat_1.html#NM1">Nat</a>  st <font color="Maroon">S<sub>1</sub></font>[<font color="Olive">x</font>] holds <br/><font color="Maroon">S<sub>1</sub></font>[<font color="Olive">x</font> <a href="xcmplx_0.html#K2">+</a> 1]
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="41_1_2"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">x</font> be   <a href="nat_1.html#NM1">Nat</a>;<br/>

<b>assume </b><a NAME="E1:41_1_2"/><i><font color="Green">E38</font></i>: 
<font color="Maroon">S<sub>1</sub></font>[<font color="Maroon">x</font>]
 ;<br/>

<a NAME="E2:41_1_2"/>
<font color="Maroon">x</font> <a href="xxreal_0.html#R1">&lt;=</a> <font color="Maroon">x</font> <a href="xcmplx_0.html#K2">+</a> 1
 
<b>by </b><i><a class="ref" href="nat_1.html#T29">NAT_1:29</a></i>;<br/>
<b>hence </b><a NAME="E3:41_1_2"/>
<font color="Maroon">S<sub>1</sub></font>[<font color="Maroon">x</font> <a href="xcmplx_0.html#K2">+</a> 1]
 <b>by </b><i><a class="txt" href="real_3.html#E4:41_1"><i><font color="Green">E33</font></i></a>, </i>;<br/>


</div><b>end;</b></div>
<a NAME="E5:41_1"/>
for <font color="Olive">n</font> being  <a href="nat_1.html#NM1">Nat</a> holds  <font color="Maroon">S<sub>1</sub></font>[<font color="Olive">n</font>]
 
<b>from </b><i><a class="ref" href="nat_1.html#S2">NAT_1:sch 2</a>(<a class="txt" href="real_3.html#E1:41"><i><font color="Green">E31</font></i></a>, <a class="txt" href="real_3.html#E3:41_1"><i><font color="Green">E32</font></i></a>);<br/></i>
<a NAME="E6:41_1"/><b>then </b>
<span class="p1">(<span class="default"><a href="real_3.html#K1" target="_self">modSeq</a> 0,<font color="Maroon">n</font></span>)</span> <a href="funct_2.html#K3">.</a> <font color="Maroon">x</font> <a href="hidden.html#R1">=</a> 0
 
;<br/>
<b>hence </b><a NAME="E7:41_1"/>
<span class="p1">(<span class="default"><a href="real_3.html#K1" target="_self">modSeq</a> 0,<font color="Maroon">n</font></span>)</span> <a href="seq_1.html#K2">.</a> <font color="Maroon">x</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><a href="numbers.html#K5">NAT</a>  <a href="funcop_1.html#K2">--&gt;</a> 0</span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">x</font>
 <b>by </b><i><a class="ref" href="funcop_1.html#T13">FUNCOP_1:13</a></i>;<br/>


</div><b>end;</b></div>
<b>hence </b><a NAME="E3:41"/>
 <a href="real_3.html#K1" target="_self">modSeq</a> 0,<font color="Maroon">n</font> <a href="hidden.html#R1">=</a> <a href="numbers.html#K5">NAT</a>  <a href="funcop_1.html#K2">--&gt;</a> 0
 <b>by </b><i>, , <a class="ref" href="funct_1.html#T9">FUNCT_1:9</a></i>;<br/>


</div>
