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

<a NAME="E1:8_1_1"/><i><font color="Green">E7</font></i>: 
0 <a href="hidden.html#R2">in</a>  <a href="numbers.html#K5">NAT</a> 
 
;<br/>
<b>reconsider </b><font color="Maroon">c<sub>4</sub></font> = 0 as    <a href="subset_1.html#M1">Element</a> of <font color="Maroon">c<sub>1</sub></font> <b>by </b><i><a class="txt" href="prgcor_2.html#E1:8_1_1"><i><font color="Green">E7</font></i></a>, <a class="txt" href="prgcor_2.html#E1:8"><i><font color="Green">E6</font></i></a></i>;<br/>
<b>reconsider </b><font color="Maroon">c<sub>5</sub></font> = <span class="p1">(<span class="default"><span class="p2">(<span class="default"><font color="Maroon">c<sub>3</sub></font> <a href="binarith.html#K5">-'</a> <span class="p3">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="binarith.html#K5">-'</a> 1</span>)</span> <a href="funcop_1.html#K2">--&gt;</a> <font color="Maroon">c<sub>4</sub></font> as   <a href="afinsq_1.html#NM2">XFinSequence</a> of <font color="Maroon">c<sub>1</sub></font> <b>by </b><i><a class="ref" href="prgcor_2.html#T4" target="_self">Th4</a></i>;<br/>
<a NAME="E4:8_1_1"/><i><font color="Green">E8</font></i>: 
 <a href="afinsq_1.html#K1">len</a> <font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>3</sub></font> <a href="binarith.html#K5">-'</a> <span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="binarith.html#K5">-'</a> 1
 
<b>by </b><i><a class="ref" href="prgcor_2.html#T4" target="_self">Th4</a></i>;<br/>
<a NAME="E5:8_1_1"/><i><font color="Green">E9</font></i>: 
<font color="Maroon">c<sub>3</sub></font> <a href="real_1.html#K5">-</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="xxreal_0.html#NR4" target="_self">&gt;</a> 0
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E1:8"><i><font color="Green">E6</font></i></a>, <a class="ref" href="xreal_1.html#T52">XREAL_1:52</a></i>;<br/>
<a NAME="E6:8_1_1"/><b>then </b><i><font color="Green">E10</font></i>: 
<font color="Maroon">c<sub>3</sub></font> <a href="binarith.html#K5">-'</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>3</sub></font> <a href="real_1.html#K5">-</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span>
 
<b>by </b><i><a class="ref" href="binarith.html#D3">BINARITH:def 3</a></i>;<br/>
<a NAME="E7:8_1_1"/><b>then </b>
<font color="Maroon">c<sub>3</sub></font> <a href="binarith.html#K5">-'</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> 0 <a href="nat_1.html#K1">+</a> 1
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E5:8_1_1"><i><font color="Green">E9</font></i></a>, <a class="ref" href="nat_1.html#T38">NAT_1:38</a></i>;<br/>
<a NAME="E8:8_1_1"/><b>then </b><i><font color="Green">E11</font></i>: 
<span class="p1">(<span class="default"><font color="Maroon">c<sub>3</sub></font> <a href="binarith.html#K5">-'</a> <span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="real_1.html#K5">-</a> 1 <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> 0
 
<b>by </b><i><a class="ref" href="xreal_1.html#T50">XREAL_1:50</a></i>;<br/>
<a NAME="E9:8_1_1"/>
 <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font> <a href="hidden.html#R2">in</a>  <a href="numbers.html#K5">NAT</a> 
 
;<br/>
<b>then reconsider </b><font color="Maroon">c<sub>6</sub></font> =  <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font> as    <a href="subset_1.html#M1">Element</a> of <font color="Maroon">c<sub>1</sub></font> <b>by </b><i><a class="txt" href="prgcor_2.html#E1:8"><i><font color="Green">E6</font></i></a></i>;<br/>
<a NAME="E11:8_1_1"/>
<span class="p1"><a href="tarski.html#K1">{</a><span class="default"><span class="p2"><a href="tarski.html#K4">[</a><span class="default">0,<font color="Maroon">c<sub>6</sub></font></span><a href="tarski.html#K4">]</a></span></span><a href="tarski.html#K1">}</a></span> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="xboole_0.html#K1">{}</a> 
 
;<br/>
<a NAME="E12:8_1_1"/><b>then </b>
<span class="p1"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="xboole_0.html#K1">{}</a> 
 
<b>by </b><i><a class="ref" href="afinsq_1.html#D2">AFINSQ_1:def 2</a></i>;<br/>
<a NAME="E13:8_1_1"/><b>then </b><i><font color="Green">E12</font></i>: 
<span class="p1"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p1">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="xboole_0.html#K1">{}</a> 
 
<b>by </b><i><a class="ref" href="afinsq_1.html#T33">AFINSQ_1:33</a></i>;<br/>
<b>reconsider </b><font color="Maroon">c<sub>7</sub></font> = <span class="p1">(<span class="default"><span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="afinsq_1.html#K5">^</a> <font color="Maroon">c<sub>5</sub></font> as  non <a href="xboole_0.html#V1">empty</a> <a href="afinsq_1.html#NM2">XFinSequence</a> of <font color="Maroon">c<sub>1</sub></font> <b>by </b><i><a class="txt" href="prgcor_2.html#E13:8_1_1"><i><font color="Green">E12</font></i></a>, <a class="ref" href="afinsq_1.html#T33">AFINSQ_1:33</a></i>;<br/>
<i><font color="Green">E13</font></i>:  <a href="afinsq_1.html#K1">len</a> <font color="Maroon">c<sub>7</sub></font> = 
<span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2">(<span class="default"><span class="p3"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p3">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span></span>)</span> <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <font color="Maroon">c<sub>5</sub></font></span>)</span>
<b>by </b><i><a class="ref" href="afinsq_1.html#T20">AFINSQ_1:20</a></i>
<br/>.= 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p3"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span></span>)</span> <a href="nat_1.html#K1">+</a> <span class="p2">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p3">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span></span>)</span> <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <font color="Maroon">c<sub>5</sub></font></span>)</span>
<b>by </b><i><a class="ref" href="afinsq_1.html#T20">AFINSQ_1:20</a></i>
<br/>.= 
<span class="p1">(<span class="default">1 <a href="nat_1.html#K1">+</a> <span class="p2">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p3">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span></span>)</span> <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <font color="Maroon">c<sub>5</sub></font></span>)</span>
<b>by </b><i><a class="ref" href="afinsq_1.html#T37">AFINSQ_1:37</a></i>
<br/>.= 
<span class="p1">(<span class="default">1 <a href="nat_1.html#K1">+</a> <span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <font color="Maroon">c<sub>5</sub></font></span>)</span>
<b>by </b><i><a class="ref" href="prgcor_2.html#D1" target="_self">Def1</a></i>
<br/>.= 
<span class="p1">(<span class="default">1 <a href="nat_1.html#K1">+</a> <span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><font color="Maroon">c<sub>3</sub></font> <a href="binarith.html#K5">-'</a> <span class="p3">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="binarith.html#K5">-'</a> 1</span>)</span>
<b>by </b><i><a class="ref" href="prgcor_2.html#T4" target="_self">Th4</a></i>
<br/>.= 
<span class="p1">(<span class="default"><font color="Maroon">c<sub>3</sub></font> <a href="real_1.html#K5">-</a> <span class="p2">(<span class="default"><span class="p3">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="nat_1.html#K1">+</a> 1</span>)</span></span>)</span> <a href="real_1.html#K3">+</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="nat_1.html#K1">+</a> 1</span>)</span>
<b>by </b><i><a class="txt" href="prgcor_2.html#E8:8_1_1"><i><font color="Green">E11</font></i></a>, <a class="txt" href="prgcor_2.html#E6:8_1_1"><i><font color="Green">E10</font></i></a>, <a class="ref" href="binarith.html#D3">BINARITH:def 3</a></i>
<br/>.= 
<font color="Maroon">c<sub>3</sub></font>

;<br/>
<a NAME="E16:8_1_1"/>
0 <a href="hidden.html#R2">in</a> 1
 
<b>by </b><i><a class="ref" href="prgcor_2.html#T1" target="_self">Th1</a></i>;<br/>
<a NAME="E17:8_1_1"/><b>then </b><i><font color="Green">E14</font></i>: 
0 <a href="hidden.html#R2">in</a>  <a href="afinsq_1.html#K2">dom</a> <span class="p1"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span>
 
<b>by </b><i><a class="ref" href="afinsq_1.html#D5">AFINSQ_1:def 5</a></i>;<br/>
<a NAME="E18:8_1_1"/>
 <a href="afinsq_1.html#K2">dom</a> <span class="p1"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="hidden.html#R1">=</a> 1
 
<b>by </b><i><a class="ref" href="afinsq_1.html#D5">AFINSQ_1:def 5</a></i>;<br/>
<a NAME="E19:8_1_1"/><b>then </b><i><font color="Green">E15</font></i>: 
 <a href="afinsq_1.html#K1">len</a> <span class="p1"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="hidden.html#R1">=</a> 1
 
<b>by </b><i><a class="ref" href="afinsq_1.html#D1">AFINSQ_1:def 1</a></i>;<br/>
<a NAME="E20:8_1_1"/>
0 <a href="xxreal_0.html#NR3" target="_self">&lt;</a> 1 <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span>
 
;<br/>
<a NAME="E21:8_1_1"/><b>then </b>
0 <a href="hidden.html#R2">in</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span></span>)</span> <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span>
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E19:8_1_1"><i><font color="Green">E15</font></i></a>, <a class="ref" href="prgcor_2.html#T1" target="_self">Th1</a></i>;<br/>
<a NAME="E22:8_1_1"/><b>then </b>
0 <a href="hidden.html#R2">in</a>  <a href="afinsq_1.html#K1">len</a> <span class="p1">(<span class="default"><span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="afinsq_1.html#T20">AFINSQ_1:20</a></i>;<br/>
<a NAME="E23:8_1_1"/><b>then </b>
0 <a href="hidden.html#R2">in</a>  <a href="afinsq_1.html#K2">dom</a> <span class="p1">(<span class="default"><span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="afinsq_1.html#D1">AFINSQ_1:def 1</a></i>;<br/>
<b>then </b><i><font color="Green">E16</font></i>: <font color="Maroon">c<sub>7</sub></font> <a href="funct_1.html#K1">.</a> 0 = 
<span class="p1">(<span class="default"><span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> 0
<b>by </b><i><a class="ref" href="afinsq_1.html#D4">AFINSQ_1:def 4</a></i>
<br/>.= 
<span class="p1"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="funct_1.html#K1">.</a> 0
<b>by </b><i><a class="txt" href="prgcor_2.html#E17:8_1_1"><i><font color="Green">E14</font></i></a>, <a class="ref" href="afinsq_1.html#D4">AFINSQ_1:def 4</a></i>
<br/>.= 
<font color="Maroon">c<sub>6</sub></font>
<b>by </b><i><a class="ref" href="afinsq_1.html#D5">AFINSQ_1:def 5</a></i>
;<br/>
<a NAME="E25:8_1_1"/><i><font color="Green">E17</font></i>: 
for <font color="Olive">b<sub>1</sub></font> being  <a href="nat_1.html#NM1">Nat</a> st 1 <a href="xxreal_0.html#R1">&lt;=</a> <font color="Olive">b<sub>1</sub></font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="xxreal_0.html#R1">&lt;=</a>  <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font> holds <br/><font color="Maroon">c<sub>7</sub></font> <a href="funct_1.html#K1">.</a> <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>2</sub></font> <a href="funct_1.html#K1">.</a> <font color="Olive">b<sub>1</sub></font>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="8_1_1_3"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">c<sub>8</sub></font> be   <a href="nat_1.html#NM1">Nat</a>;<br/>

<b>assume </b><a NAME="E1:8_1_1_3"/><i><font color="Green">E18</font></i>: 
( 1 <a href="xxreal_0.html#R1">&lt;=</a> <font color="Maroon">c<sub>8</sub></font> &amp; <font color="Maroon">c<sub>8</sub></font> <a href="xxreal_0.html#R1">&lt;=</a>  <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font> )
 ;<br/>

<a NAME="E2:8_1_1_3"/><b>then </b>
<font color="Maroon">c<sub>8</sub></font> <a href="real_1.html#K5">-</a> 1 <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> 0
 
<b>by </b><i><a class="ref" href="xreal_1.html#T50">XREAL_1:50</a></i>;<br/>
<a NAME="E3:8_1_1_3"/><b>then </b><i><font color="Green">E19</font></i>: 
<font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> 1 <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>8</sub></font> <a href="real_1.html#K5">-</a> 1
 
<b>by </b><i><a class="ref" href="binarith.html#D3">BINARITH:def 3</a></i>;<br/>
<a NAME="E4:8_1_1_3"/>
<font color="Maroon">c<sub>8</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Maroon">c<sub>8</sub></font> <a href="nat_1.html#K1">+</a> 1
 
<b>by </b><i><a class="ref" href="nat_1.html#T38">NAT_1:38</a></i>;<br/>
<a NAME="E5:8_1_1_3"/><b>then </b>
<font color="Maroon">c<sub>8</sub></font> <a href="real_1.html#K5">-</a> 1 <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>8</sub></font> <a href="nat_1.html#K1">+</a> 1</span>)</span> <a href="real_1.html#K5">-</a> 1
 
<b>by </b><i><a class="ref" href="xreal_1.html#T11">XREAL_1:11</a></i>;<br/>
<a NAME="E6:8_1_1_3"/><b>then </b><i><font color="Green">E20</font></i>: 
<font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> 1 <a href="xxreal_0.html#NR3" target="_self">&lt;</a>  <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font>
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E1:8_1_1_3"><i><font color="Green">E18</font></i></a>, <a class="txt" href="prgcor_2.html#E3:8_1_1_3"><i><font color="Green">E19</font></i></a>, <a class="ref" href="xreal_1.html#T2">XREAL_1:2</a></i>;<br/>
<a NAME="E7:8_1_1_3"/><b>then </b>
<font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> 1 <a href="hidden.html#R2">in</a>  <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font>
 
<b>by </b><i><a class="ref" href="prgcor_2.html#T1" target="_self">Th1</a></i>;<br/>
<a NAME="E8:8_1_1_3"/><b>then </b>
<font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> 1 <a href="hidden.html#R2">in</a>  <a href="afinsq_1.html#K1">len</a> <span class="p1">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span>
 
<b>by </b><i><a class="ref" href="prgcor_2.html#D1" target="_self">Def1</a></i>;<br/>
<a NAME="E9:8_1_1_3"/><b>then </b><i><font color="Green">E21</font></i>: 
<font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> 1 <a href="hidden.html#R2">in</a>  <a href="afinsq_1.html#K2">dom</a> <span class="p1">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span>
 
<b>by </b><i><a class="ref" href="afinsq_1.html#D1">AFINSQ_1:def 1</a></i>;<br/>
<a NAME="E10:8_1_1_3"/>
<font color="Maroon">c<sub>8</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> 1 <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span>
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E1:8_1_1_3"><i><font color="Green">E18</font></i></a>, <a class="ref" href="nat_1.html#T38">NAT_1:38</a></i>;<br/>
<a NAME="E11:8_1_1_3"/><b>then </b>
<font color="Maroon">c<sub>8</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span></span>)</span> <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span>
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E19:8_1_1"><i><font color="Green">E15</font></i></a>, <a class="ref" href="prgcor_2.html#D1" target="_self">Def1</a></i>;<br/>
<a NAME="E12:8_1_1_3"/><b>then </b>
<font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R2">in</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span></span>)</span> <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="prgcor_2.html#T1" target="_self">Th1</a></i>;<br/>
<a NAME="E13:8_1_1_3"/><b>then </b>
<font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R2">in</a>  <a href="afinsq_1.html#K1">len</a> <span class="p1">(<span class="default"><span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="afinsq_1.html#T20">AFINSQ_1:20</a></i>;<br/>
<a NAME="E14:8_1_1_3"/><b>then </b>
<font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R2">in</a>  <a href="afinsq_1.html#K2">dom</a> <span class="p1">(<span class="default"><span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="afinsq_1.html#D1">AFINSQ_1:def 1</a></i>;<br/>
<b>then </b><font color="Maroon">c<sub>7</sub></font> <a href="funct_1.html#K1">.</a> <font color="Maroon">c<sub>8</sub></font> = 
<span class="p1">(<span class="default"><span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="funct_1.html#K1">.</a> <span class="p1">(<span class="default">1 <a href="nat_1.html#K1">+</a> <span class="p2">(<span class="default"><font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> 1</span>)</span></span>)</span>
<b>by </b><i><a class="txt" href="prgcor_2.html#E3:8_1_1_3"><i><font color="Green">E19</font></i></a>, <a class="ref" href="afinsq_1.html#D4">AFINSQ_1:def 4</a></i>
<br/>.= 
<span class="p1">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="funct_1.html#K1">.</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> 1</span>)</span>
<b>by </b><i><a class="txt" href="prgcor_2.html#E19:8_1_1"><i><font color="Green">E15</font></i></a>, <a class="txt" href="prgcor_2.html#E9:8_1_1_3"><i><font color="Green">E21</font></i></a>, <a class="ref" href="afinsq_1.html#D4">AFINSQ_1:def 4</a></i>
<br/>.= 
<font color="Maroon">c<sub>2</sub></font> <a href="funct_1.html#K1">.</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> 1</span>)</span> <a href="nat_1.html#K1">+</a> 1</span>)</span>
<b>by </b><i><a class="txt" href="prgcor_2.html#E6:8_1_1_3"><i><font color="Green">E20</font></i></a>, <a class="ref" href="prgcor_2.html#D1" target="_self">Def1</a></i>
<br/>.= 
<font color="Maroon">c<sub>2</sub></font> <a href="funct_1.html#K1">.</a> <font color="Maroon">c<sub>8</sub></font>
<b>by </b><i><a class="txt" href="prgcor_2.html#E3:8_1_1_3"><i><font color="Green">E19</font></i></a></i>
;<br/>
<b>hence </b><a NAME="E16:8_1_1_3"/>
<font color="Maroon">c<sub>7</sub></font> <a href="funct_1.html#K1">.</a> <font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>2</sub></font> <a href="funct_1.html#K1">.</a> <font color="Maroon">c<sub>8</sub></font>
 ;<br/>


</div><b>end;</b></div>
<a NAME="E26:8_1_1"/>
for <font color="Olive">b<sub>1</sub></font> being  <a href="nat_1.html#NM1">Nat</a> st  <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Olive">b<sub>1</sub></font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Maroon">c<sub>3</sub></font> holds <br/><font color="Maroon">c<sub>7</sub></font> <a href="funct_1.html#K1">.</a> <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1">=</a> 0
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="8_1_1_4"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">c<sub>8</sub></font> be   <a href="nat_1.html#NM1">Nat</a>;<br/>

<b>assume </b><a NAME="E1:8_1_1_4"/><i><font color="Green">E18</font></i>: 
(  <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Maroon">c<sub>8</sub></font> &amp; <font color="Maroon">c<sub>8</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Maroon">c<sub>3</sub></font> )
 ;<br/>

<i><font color="Green">E19</font></i>:  <a href="afinsq_1.html#K1">len</a> <span class="p1">(<span class="default"><span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> = 
<span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span></span>)</span> <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span>
<b>by </b><i><a class="ref" href="afinsq_1.html#T20">AFINSQ_1:20</a></i>
<br/>.= 
1 <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span>
<b>by </b><i><a class="txt" href="prgcor_2.html#E19:8_1_1"><i><font color="Green">E15</font></i></a>, <a class="ref" href="prgcor_2.html#D1" target="_self">Def1</a></i>
;<br/>
<a NAME="E3:8_1_1_4"/>
1 <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="xxreal_0.html#R1">&lt;=</a> <font color="Maroon">c<sub>8</sub></font>
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E1:8_1_1_4"><i><font color="Green">E18</font></i></a>, <a class="ref" href="nat_1.html#T38">NAT_1:38</a></i>;<br/>
<a NAME="E4:8_1_1_4"/><b>then </b>
<font color="Maroon">c<sub>8</sub></font> <a href="real_1.html#K5">-</a> <span class="p1">(<span class="default">1 <a href="nat_1.html#K1">+</a> <span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> 0
 
<b>by </b><i><a class="ref" href="xreal_1.html#T50">XREAL_1:50</a></i>;<br/>
<a NAME="E5:8_1_1_4"/><b>then </b><i><font color="Green">E20</font></i>: 
<font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> <span class="p1">(<span class="default">1 <a href="nat_1.html#K1">+</a> <span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>8</sub></font> <a href="real_1.html#K5">-</a> <span class="p1">(<span class="default">1 <a href="nat_1.html#K1">+</a> <span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="binarith.html#D3">BINARITH:def 3</a></i>;<br/>
<a NAME="E6:8_1_1_4"/>
 <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Maroon">c<sub>3</sub></font>
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E1:8_1_1_4"><i><font color="Green">E18</font></i></a>, <a class="ref" href="xreal_1.html#T2">XREAL_1:2</a></i>;<br/>
<a NAME="E7:8_1_1_4"/><b>then </b><i><font color="Green">E21</font></i>: 
<font color="Maroon">c<sub>3</sub></font> <a href="real_1.html#K5">-</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="xxreal_0.html#NR4" target="_self">&gt;</a> 0
 
<b>by </b><i><a class="ref" href="xreal_1.html#T52">XREAL_1:52</a></i>;<br/>
<a NAME="E8:8_1_1_4"/><b>then </b><i><font color="Green">E22</font></i>: 
<font color="Maroon">c<sub>3</sub></font> <a href="binarith.html#K5">-'</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>3</sub></font> <a href="real_1.html#K5">-</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span>
 
<b>by </b><i><a class="ref" href="binarith.html#D3">BINARITH:def 3</a></i>;<br/>
<a NAME="E9:8_1_1_4"/><b>then </b>
<font color="Maroon">c<sub>3</sub></font> <a href="real_1.html#K5">-</a> <span class="p1">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> 0 <a href="nat_1.html#K1">+</a> 1
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E7:8_1_1_4"><i><font color="Green">E21</font></i></a>, <a class="ref" href="nat_1.html#T38">NAT_1:38</a></i>;<br/>
<a NAME="E10:8_1_1_4"/><b>then </b>
<span class="p1">(<span class="default"><font color="Maroon">c<sub>3</sub></font> <a href="binarith.html#K5">-'</a> <span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="real_1.html#K5">-</a> 1 <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> 0
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E8:8_1_1_4"><i><font color="Green">E22</font></i></a>, <a class="ref" href="xreal_1.html#T50">XREAL_1:50</a></i>;<br/>
<a NAME="E11:8_1_1_4"/><b>then </b><i><font color="Green">E23</font></i>: 
<span class="p1">(<span class="default"><font color="Maroon">c<sub>3</sub></font> <a href="binarith.html#K5">-'</a> <span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="binarith.html#K5">-'</a> 1 <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>3</sub></font> <a href="real_1.html#K5">-</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="nat_1.html#K1">+</a> 1</span>)</span>
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E8:8_1_1_4"><i><font color="Green">E22</font></i></a>, <a class="ref" href="binarith.html#D3">BINARITH:def 3</a></i>;<br/>
<a NAME="E12:8_1_1_4"/>
<font color="Maroon">c<sub>8</sub></font> <a href="real_1.html#K5">-</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="nat_1.html#K1">+</a> 1</span>)</span> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Maroon">c<sub>3</sub></font> <a href="real_1.html#K5">-</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="nat_1.html#K1">+</a> 1</span>)</span>
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E1:8_1_1_4"><i><font color="Green">E18</font></i></a>, <a class="ref" href="xreal_1.html#T11">XREAL_1:11</a></i>;<br/>
<a NAME="E13:8_1_1_4"/><b>then </b><i><font color="Green">E24</font></i>: 
<font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2">(<span class="default"><span class="p3"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p3">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span></span>)</span> <a href="hidden.html#R2">in</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>3</sub></font> <a href="binarith.html#K5">-'</a> <span class="p2">(<span class="default"><a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span> <a href="binarith.html#K5">-'</a> 1
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E2:8_1_1_4"><i><font color="Green">E19</font></i></a>, <a class="txt" href="prgcor_2.html#E5:8_1_1_4"><i><font color="Green">E20</font></i></a>, <a class="txt" href="prgcor_2.html#E11:8_1_1_4"><i><font color="Green">E23</font></i></a>, <a class="ref" href="prgcor_2.html#T1" target="_self">Th1</a></i>;<br/>
<a NAME="E14:8_1_1_4"/><b>then </b><i><font color="Green">E25</font></i>: 
<font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2">(<span class="default"><span class="p3"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p3">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span></span>)</span> <a href="hidden.html#R2">in</a>  <a href="afinsq_1.html#K2">dom</a> <font color="Maroon">c<sub>5</sub></font>
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E4:8_1_1"><i><font color="Green">E8</font></i></a>, <a class="ref" href="afinsq_1.html#D1">AFINSQ_1:def 1</a></i>;<br/>
<a NAME="E15:8_1_1_4"/>
<font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p2">(<span class="default"><span class="p3"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p3">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span></span>)</span> <a href="nat_1.html#K1">+</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> <span class="p2">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p3">(<span class="default"><span class="p4"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p4">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span></span>)</span></span>)</span>
 
<b>by </b><i><a class="txt" href="prgcor_2.html#E2:8_1_1_4"><i><font color="Green">E19</font></i></a>, <a class="txt" href="prgcor_2.html#E5:8_1_1_4"><i><font color="Green">E20</font></i></a></i>;<br/>
<b>then </b><font color="Maroon">c<sub>7</sub></font> <a href="funct_1.html#K1">.</a> <font color="Maroon">c<sub>8</sub></font> = 
<font color="Maroon">c<sub>5</sub></font> <a href="funct_1.html#K1">.</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>8</sub></font> <a href="binarith.html#K5">-'</a> <span class="p2">(<span class="default"><a href="afinsq_1.html#K1">len</a> <span class="p3">(<span class="default"><span class="p4"><a href="afinsq_1.html#K9">&lt;%</a><span class="default"><font color="Maroon">c<sub>6</sub></font></span><a href="afinsq_1.html#K9">%&gt;</a></span> <a href="afinsq_1.html#K5">^</a> <span class="p4">(<span class="default"><a href="prgcor_2.html#K1" target="_self">FS2XFS</a> <font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span></span>)</span></span>)</span>
<b>by </b><i><a class="txt" href="prgcor_2.html#E14:8_1_1_4"><i><font color="Green">E25</font></i></a>, <a class="ref" href="afinsq_1.html#D4">AFINSQ_1:def 4</a></i>
<br/>.= 
0
<b>by </b><i><a class="txt" href="prgcor_2.html#E13:8_1_1_4"><i><font color="Green">E24</font></i></a>, <a class="ref" href="funcop_1.html#T13">FUNCOP_1:13</a></i>
;<br/>
<b>hence </b><a NAME="E17:8_1_1_4"/>
<font color="Maroon">c<sub>7</sub></font> <a href="funct_1.html#K1">.</a> <font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R1">=</a> 0
 ;<br/>


</div><b>end;</b></div>
<b>hence </b><a NAME="E27:8_1_1"/>
ex <font color="Olive">b<sub>1</sub></font> being non <a href="xboole_0.html#V1">empty</a> <a href="afinsq_1.html#NM2">XFinSequence</a> of <font color="Maroon">c<sub>1</sub></font> st <br/>(  <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font> <a href="hidden.html#R1">=</a> <font color="Olive">b<sub>1</sub></font> <a href="funct_1.html#K1">.</a> 0 &amp;  <a href="afinsq_1.html#K1">len</a> <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>3</sub></font> &amp; ( for <font color="Olive">b<sub>2</sub></font> being  <a href="nat_1.html#NM1">Nat</a> st 1 <a href="xxreal_0.html#R1">&lt;=</a> <font color="Olive">b<sub>2</sub></font> &amp; <font color="Olive">b<sub>2</sub></font> <a href="xxreal_0.html#R1">&lt;=</a>  <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font> holds <br/><font color="Olive">b<sub>1</sub></font> <a href="funct_1.html#K1">.</a> <font color="Olive">b<sub>2</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>2</sub></font> <a href="funct_1.html#K1">.</a> <font color="Olive">b<sub>2</sub></font> ) &amp; ( for <font color="Olive">b<sub>2</sub></font> being  <a href="nat_1.html#NM1">Nat</a> st  <a href="finseq_1.html#K3">len</a> <font color="Maroon">c<sub>2</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Olive">b<sub>2</sub></font> &amp; <font color="Olive">b<sub>2</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Maroon">c<sub>3</sub></font> holds <br/><font color="Olive">b<sub>1</sub></font> <a href="funct_1.html#K1">.</a> <font color="Olive">b<sub>2</sub></font> <a href="hidden.html#R1">=</a> 0 ) )
 <b>by </b><i><a class="txt" href="prgcor_2.html#E15:8_1_1"><i><font color="Green">E13</font></i></a>, <a class="txt" href="prgcor_2.html#E24:8_1_1"><i><font color="Green">E16</font></i></a>, <a class="txt" href="prgcor_2.html#E25:8_1_1"><i><font color="Green">E17</font></i></a></i>;<br/>


</div>
