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

<b>let </b><font color="Maroon">c<sub>1</sub></font> be   <a href="diraf.html#NM2">AffinPlane</a>;<br/>

<b>assume </b><a NAME="E1:23"/><i><font color="Green">E9</font></i>: 
<font color="Maroon">c<sub>1</sub></font> <a href="aff_3.html#NR6" target="_self">satisfies_DES2_1</a> 
 ;<br/>

<b>let </b><font color="Maroon">c<sub>2</sub></font> be   <a href="struct_0.html#NM2">Subset</a> of <font color="Maroon">c<sub>1</sub></font>; <i><font color="Red">:: according to </font></i><a class="ref" href="aff_3.html#D5" target="_self">AFF_3:def 5</a><br/><b>let </b><font color="Maroon">c<sub>3</sub></font>, <font color="Maroon">c<sub>4</sub></font> be   <a href="struct_0.html#NM2">Subset</a> of <font color="Maroon">c<sub>1</sub></font>;<br/><b>let </b><font color="Maroon">c<sub>5</sub></font>, <font color="Maroon">c<sub>6</sub></font>, <font color="Maroon">c<sub>7</sub></font>, <font color="Maroon">c<sub>8</sub></font>, <font color="Maroon">c<sub>9</sub></font>, <font color="Maroon">c<sub>10</sub></font>, <font color="Maroon">c<sub>11</sub></font>, <font color="Maroon">c<sub>12</sub></font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">c<sub>1</sub></font>;<br/>





















<b>assume </b><b>that </b><br/><a NAME="E2:23"/><i><font color="Green">E10</font></i>: 
( <font color="Maroon">c<sub>2</sub></font> <a href="aff_1.html#NR2" target="_self">is_line</a>  &amp; <font color="Maroon">c<sub>3</sub></font> <a href="aff_1.html#NR2" target="_self">is_line</a>  &amp; <font color="Maroon">c<sub>4</sub></font> <a href="aff_1.html#NR2" target="_self">is_line</a>  )
 <b>and </b><br/><a NAME="E3:23"/><i><font color="Green">E11</font></i>: 
( <font color="Maroon">c<sub>2</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>3</sub></font> &amp; <font color="Maroon">c<sub>2</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>4</sub></font> &amp; <font color="Maroon">c<sub>3</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>4</sub></font> )
 <b>and </b><br/><a NAME="E4:23"/><i><font color="Green">E12</font></i>: 
( <font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>2</sub></font> &amp; <font color="Maroon">c<sub>6</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>2</sub></font> &amp; <font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>3</sub></font> &amp; <font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>3</sub></font> &amp; <font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>4</sub></font> &amp; <font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>4</sub></font> &amp; <font color="Maroon">c<sub>2</sub></font> <a href="aff_1.html#R4">//</a> <font color="Maroon">c<sub>3</sub></font> &amp; <font color="Maroon">c<sub>2</sub></font> <a href="aff_1.html#R4">//</a> <font color="Maroon">c<sub>4</sub></font> &amp; not  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> &amp; not  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> &amp; <font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>12</sub></font> &amp; <font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>6</sub></font> )
 <b>and </b><br/><a NAME="E5:23"/><i><font color="Green">E13</font></i>: 
(  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>11</sub></font> &amp;  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>11</sub></font> &amp;  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font>,<font color="Maroon">c<sub>12</sub></font> &amp;  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font>,<font color="Maroon">c<sub>12</sub></font> &amp; <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> )
 ;<br/>

<a NAME="E6:23"/><i><font color="Green">E14</font></i>: 
<font color="Maroon">c<sub>3</sub></font> <a href="aff_1.html#R4">//</a> <font color="Maroon">c<sub>4</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T58">AFF_1:58</a></i>;<br/>
<a NAME="E7:23"/><i><font color="Green">E15</font></i>: 
( <font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>7</sub></font> &amp; <font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>9</sub></font> &amp; <font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>9</sub></font> &amp; <font color="Maroon">c<sub>6</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>8</sub></font> &amp; <font color="Maroon">c<sub>6</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>10</sub></font> &amp; <font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>10</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T16">AFF_1:16</a></i>;<br/>
<b>set </b><font color="Maroon">c<sub>13</sub></font> =  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font>;<br/>
<b>set </b><font color="Maroon">c<sub>14</sub></font> =  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font>;<br/>
<b>set </b><font color="Maroon">c<sub>15</sub></font> =  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font>;<br/>
<b>set </b><font color="Maroon">c<sub>16</sub></font> =  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font>;<br/>
<a NAME="E8:23"/><i><font color="Green">E16</font></i>: 
(  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="aff_1.html#NR2" target="_self">is_line</a>  &amp;  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="aff_1.html#NR2" target="_self">is_line</a>  &amp;  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="aff_1.html#NR2" target="_self">is_line</a>  &amp;  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="aff_1.html#NR2" target="_self">is_line</a>  &amp; <font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> &amp; <font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> &amp; <font color="Maroon">c<sub>6</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> &amp; <font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> &amp; <font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> &amp; <font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> &amp; <font color="Maroon">c<sub>12</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> &amp; <font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font> &amp; <font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font> &amp; <font color="Maroon">c<sub>12</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E5:23"><i><font color="Green">E13</font></i></a>, <a class="txt" href="aff_3.html#E7:23"><i><font color="Green">E15</font></i></a>, <a class="ref" href="aff_1.html#T26">AFF_1:26</a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a>, <a class="ref" href="aff_1.html#D3">AFF_1:def 3</a></i>;<br/>
<a NAME="E9:23"/><i><font color="Green">E17</font></i>: 
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="aff_1.html#R4">//</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E5:23"><i><font color="Green">E13</font></i></a>, <a class="txt" href="aff_3.html#E7:23"><i><font color="Green">E15</font></i></a>, <a class="ref" href="aff_1.html#T51">AFF_1:51</a></i>;<br/>
<a NAME="E10:23"/><i><font color="Green">E18</font></i>: 
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>2</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>
<a NAME="E11:23"/><i><font color="Green">E19</font></i>: 
<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>10</sub></font>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_1"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_1"/>
<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>10</sub></font>
 ;<br/>

<a NAME="E2:23_1"/><b>then </b>
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E9:23"><i><font color="Green">E17</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>
<b>hence </b><a NAME="E3:23_1"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E10:23"><i><font color="Green">E18</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/>


</div><b>end;</b></div>
<a NAME="E12:23"/><i><font color="Green">E20</font></i>: 
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_2"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_2"/>
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font>
 ;<br/>

<a NAME="E2:23_2"/><b>then </b>
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>4</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E11:23"><i><font color="Green">E19</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/>
<b>hence </b><a NAME="E3:23_2"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E6:23"><i><font color="Green">E14</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>


</div><b>end;</b></div>
<b>set </b><font color="Maroon">c<sub>17</sub></font> =  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font>;<br/>
<b>set </b><font color="Maroon">c<sub>18</sub></font> =  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font>;<br/>
<a NAME="E13:23"/><i><font color="Green">E21</font></i>: 
(  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> <a href="aff_1.html#NR2" target="_self">is_line</a>  &amp;  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> <a href="aff_1.html#NR2" target="_self">is_line</a>  &amp; <font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> &amp; <font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> &amp; <font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> &amp; <font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> &amp; <font color="Maroon">c<sub>6</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> &amp; <font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E5:23"><i><font color="Green">E13</font></i></a>, <a class="txt" href="aff_3.html#E7:23"><i><font color="Green">E15</font></i></a>, <a class="ref" href="aff_1.html#T26">AFF_1:26</a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a>, <a class="ref" href="aff_1.html#D3">AFF_1:def 3</a></i>;<br/>
<a NAME="E14:23"/><i><font color="Green">E22</font></i>: 
<font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>8</sub></font>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_3"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_3"/><i><font color="Green">E23</font></i>: 
<font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>8</sub></font>
 ;<br/>

<a NAME="E2:23_3"/><b>then </b><i><font color="Green">E24</font></i>: 
<font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>12</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E12:23"><i><font color="Green">E20</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/>
<a NAME="E3:23_3"/>
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_3_1"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_3_1"/>
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font>
 ;<br/>

<a NAME="E2:23_3_1"/><b>then </b>
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>2</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/>
<b>hence </b><a NAME="E3:23_3_1"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>


</div><b>end;</b></div>
<b>hence </b><a NAME="E4:23_3"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E1:23_3"><i><font color="Green">E23</font></i></a>, <a class="txt" href="aff_3.html#E2:23_3"><i><font color="Green">E24</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/>


</div><b>end;</b></div>
<b>consider </b><font color="Maroon">c<sub>19</sub></font> being   <a href="struct_0.html#NM2">Subset</a> of <font color="Maroon">c<sub>1</sub></font><b> such that </b><br/><a NAME="E16:23"/><i><font color="Green">E23</font></i>: 
( <font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>19</sub></font> &amp;  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="aff_1.html#R4">//</a> <font color="Maroon">c<sub>19</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="ref" href="aff_1.html#T63">AFF_1:63</a></i>;<br/>
<a NAME="E17:23"/><i><font color="Green">E24</font></i>: 
<font color="Maroon">c<sub>19</sub></font> <a href="aff_1.html#NR2" target="_self">is_line</a> 
 
<b>by </b><i><a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="ref" href="aff_1.html#T50">AFF_1:50</a></i>;<br/>
<a NAME="E18:23"/><i><font color="Green">E25</font></i>: 
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="aff_1.html#R4">//</a> <font color="Maroon">c<sub>19</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E9:23"><i><font color="Green">E17</font></i></a>, <a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="ref" href="aff_1.html#T58">AFF_1:58</a></i>;<br/>
<a NAME="E19:23"/><i><font color="Green">E26</font></i>: 
(  not <font color="Maroon">c<sub>19</sub></font> <a href="aff_1.html#R4">//</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> or  not  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="aff_1.html#R4">//</a> <font color="Maroon">c<sub>19</sub></font> )
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_4"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_4"/>
( <font color="Maroon">c<sub>19</sub></font> <a href="aff_1.html#R4">//</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> &amp;  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="aff_1.html#R4">//</a> <font color="Maroon">c<sub>19</sub></font> )
 ;<br/>

<a NAME="E2:23_4"/><b>then </b>
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="aff_1.html#R4">//</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font>
 
<b>by </b><i><a class="ref" href="aff_1.html#T58">AFF_1:58</a></i>;<br/>
<b>hence </b><a NAME="E3:23_4"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E12:23"><i><font color="Green">E20</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>


</div><b>end;</b></div>
<div><i><font color="Green">E27</font></i>: <a class="txt" onclick="hs2(this)" href="javascript:()" title="23_5"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:23_5"/>
not <font color="Maroon">c<sub>19</sub></font> <a href="aff_1.html#R4">//</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font>
 ;<br/><b>then consider </b><font color="Maroon">c<sub>20</sub></font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">c<sub>1</sub></font><b> such that </b><br/><a NAME="E3:23_5"/><i><font color="Green">E28</font></i>: 
( <font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>19</sub></font> &amp; <font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E17:23"><i><font color="Green">E24</font></i></a>, <a class="ref" href="aff_1.html#T72">AFF_1:72</a></i>;<br/><a NAME="E4:23_5"/>
not <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>20</sub></font> <a href="aff_1.html#R2">//</a> <font color="Maroon">c<sub>4</sub></font>
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_5_1"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_5_1"/><i><font color="Green">E29</font></i>: 
<font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>20</sub></font> <a href="aff_1.html#R2">//</a> <font color="Maroon">c<sub>4</sub></font>
 ;<br/>

<a NAME="E2:23_5_1"/>
<font color="Maroon">c<sub>4</sub></font> <a href="aff_1.html#R4">//</a> <font color="Maroon">c<sub>3</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T58">AFF_1:58</a></i>;<br/>
<a NAME="E3:23_5_1"/><b>then </b>
<font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>20</sub></font> <a href="aff_1.html#R2">//</a> <font color="Maroon">c<sub>3</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E1:23_5_1"><i><font color="Green">E29</font></i></a>, <a class="ref" href="aff_1.html#T57">AFF_1:57</a></i>;<br/>
<a NAME="E4:23_5_1"/><b>then </b>
<font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>3</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T37">AFF_1:37</a></i>;<br/>
<a NAME="E5:23_5_1"/><b>then </b>
( <font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>7</sub></font> or  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>3</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E3:23_5"><i><font color="Green">E28</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/>
<a NAME="E6:23_5_1"/><b>then </b><i><font color="Green">E30</font></i>: 
( <font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>11</sub></font> or <font color="Maroon">c<sub>19</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E6:23"><i><font color="Green">E14</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="txt" href="aff_3.html#E17:23"><i><font color="Green">E24</font></i></a>, <a class="txt" href="aff_3.html#E3:23_5"><i><font color="Green">E28</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_5_1_1"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:23_5_1_1"/>
<font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>11</sub></font>
 ;<br/><a NAME="E2:23_5_1_1"/><b>then </b>
 <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="ref" href="aff_1.html#T33">AFF_1:33</a></i>;<br/><a NAME="E3:23_5_1_1"/><b>then </b>
<font color="Maroon">c<sub>6</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>3</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E14:23"><i><font color="Green">E22</font></i></a>, <a class="ref" href="aff_1.html#T39">AFF_1:39</a></i>;<br/><b>hence </b><a NAME="E4:23_5_1_1"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/></div><b>end;</b></div>
<a NAME="E8:23_5_1"/><b>then </b>
<font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E18:23"><i><font color="Green">E25</font></i></a>, <a class="txt" href="aff_3.html#E6:23_5_1"><i><font color="Green">E30</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>
<b>hence </b><a NAME="E9:23_5_1"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="ref" href="aff_1.html#T33">AFF_1:33</a></i>;<br/>


</div><b>end;</b></div><b>then consider </b><font color="Maroon">c<sub>21</sub></font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">c<sub>1</sub></font><b> such that </b><br/><a NAME="E6:23_5"/><i><font color="Green">E29</font></i>: 
( <font color="Maroon">c<sub>21</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>4</sub></font> &amp;  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>20</sub></font>,<font color="Maroon">c<sub>21</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="ref" href="aff_1.html#T73">AFF_1:73</a></i>;<br/><a NAME="E7:23_5"/><i><font color="Green">E30</font></i>: 
(  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>21</sub></font>,<font color="Maroon">c<sub>20</sub></font> &amp;  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font>,<font color="Maroon">c<sub>20</sub></font> &amp; <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>11</sub></font>,<font color="Maroon">c<sub>20</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="txt" href="aff_3.html#E18:23"><i><font color="Green">E25</font></i></a>, <a class="txt" href="aff_3.html#E3:23_5"><i><font color="Green">E28</font></i></a>, <a class="txt" href="aff_3.html#E6:23_5"><i><font color="Green">E29</font></i></a>, <a class="ref" href="aff_1.html#T15">AFF_1:15</a>, <a class="ref" href="aff_1.html#T33">AFF_1:33</a>, <a class="ref" href="aff_1.html#T53">AFF_1:53</a></i>;<br/><a NAME="E8:23_5"/><i><font color="Green">E31</font></i>: 
not  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>21</sub></font>
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_5_2"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_5_2"/>
 <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>21</sub></font>
 ;<br/>

<a NAME="E2:23_5_2"/><b>then </b>
(  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>21</sub></font>,<font color="Maroon">c<sub>6</sub></font> &amp;  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>21</sub></font>,<font color="Maroon">c<sub>8</sub></font> )
 
<b>by </b><i><a class="ref" href="aff_1.html#T15">AFF_1:15</a>, <a class="ref" href="aff_1.html#T16">AFF_1:16</a></i>;<br/>
<a NAME="E3:23_5_2"/><b>then </b>
( <font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>21</sub></font> or  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>20</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E7:23_5"><i><font color="Green">E30</font></i></a>, <a class="ref" href="aff_1.html#T17">AFF_1:17</a></i>;<br/>
<a NAME="E4:23_5_2"/><b>then </b>
<font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E6:23"><i><font color="Green">E14</font></i></a>, <a class="txt" href="aff_3.html#E6:23_5"><i><font color="Green">E29</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/>
<a NAME="E5:23_5_2"/><b>then </b><i><font color="Green">E32</font></i>: 
( <font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>11</sub></font> or  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>19</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="txt" href="aff_3.html#E17:23"><i><font color="Green">E24</font></i></a>, <a class="txt" href="aff_3.html#E3:23_5"><i><font color="Green">E28</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/>
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_5_2_1"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:23_5_2_1"/>
<font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>11</sub></font>
 ;<br/><a NAME="E2:23_5_2_1"/><b>then </b>
( <font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>7</sub></font> or  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E3:23_5"><i><font color="Green">E28</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/><a NAME="E3:23_5_2_1"/><b>then </b>
(  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> or <font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="ref" href="aff_1.html#T26">AFF_1:26</a>, <a class="ref" href="aff_1.html#T33">AFF_1:33</a></i>;<br/><a NAME="E4:23_5_2_1"/><b>then </b>
<font color="Maroon">c<sub>6</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>3</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E14:23"><i><font color="Green">E22</font></i></a>, <a class="ref" href="aff_1.html#T39">AFF_1:39</a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/><b>hence </b><a NAME="E5:23_5_2_1"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/></div><b>end;</b></div>
<a NAME="E7:23_5_2"/><b>then </b>
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="txt" href="aff_3.html#E5:23_5_2"><i><font color="Green">E32</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>
<b>hence </b><a NAME="E8:23_5_2"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/>


</div><b>end;</b></div><a NAME="E9:23_5"/>
<font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>20</sub></font>
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_5_3"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_5_3"/>
<font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>20</sub></font>
 ;<br/>

<a NAME="E2:23_5_3"/><b>then </b>
( <font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>7</sub></font> or  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E3:23_5"><i><font color="Green">E28</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/>
<a NAME="E3:23_5_3"/><b>then </b>
(  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> or <font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="ref" href="aff_1.html#T26">AFF_1:26</a>, <a class="ref" href="aff_1.html#T33">AFF_1:33</a></i>;<br/>
<a NAME="E4:23_5_3"/><b>then </b>
<font color="Maroon">c<sub>6</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>3</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E14:23"><i><font color="Green">E22</font></i></a>, <a class="ref" href="aff_1.html#T39">AFF_1:39</a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/>
<b>hence </b><a NAME="E5:23_5_3"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>


</div><b>end;</b></div><a NAME="E10:23_5"/><b>then </b>
<font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>21</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E1:23"><i><font color="Green">E9</font></i></a>, <a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E5:23"><i><font color="Green">E13</font></i></a>, <a class="txt" href="aff_3.html#E6:23_5"><i><font color="Green">E29</font></i></a>, <a class="txt" href="aff_3.html#E7:23_5"><i><font color="Green">E30</font></i></a>, <a class="txt" href="aff_3.html#E8:23_5"><i><font color="Green">E31</font></i></a>, <a class="ref" href="aff_3.html#D6" target="_self">Def6</a></i>;<br/><a NAME="E11:23_5"/><b>then </b>
<font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>21</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E5:23"><i><font color="Green">E13</font></i></a>, <a class="txt" href="aff_3.html#E7:23"><i><font color="Green">E15</font></i></a>, <a class="ref" href="aff_1.html#T14">AFF_1:14</a></i>;<br/><a NAME="E12:23_5"/><b>then </b>
 <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>21</sub></font>,<font color="Maroon">c<sub>10</sub></font>
 <b>by </b><i><a class="ref" href="aff_1.html#D1">AFF_1:def 1</a></i>;<br/><a NAME="E13:23_5"/><b>then </b>
 <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font>,<font color="Maroon">c<sub>21</sub></font>
 <b>by </b><i><a class="ref" href="aff_1.html#T15">AFF_1:15</a></i>;<br/><a NAME="E14:23_5"/><b>then </b>
<font color="Maroon">c<sub>21</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font>
 <b>by </b><i><a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/><a NAME="E15:23_5"/><b>then </b>
(  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>4</sub></font> or <font color="Maroon">c<sub>21</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>10</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E6:23_5"><i><font color="Green">E29</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/><a NAME="E16:23_5"/><b>then </b>
( <font color="Maroon">c<sub>6</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>4</sub></font> or  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font>,<font color="Maroon">c<sub>20</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E6:23_5"><i><font color="Green">E29</font></i></a>, <a class="ref" href="aff_1.html#T15">AFF_1:15</a>, <a class="ref" href="aff_1.html#T26">AFF_1:26</a></i>;<br/><a NAME="E17:23_5"/><b>then </b>
<font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/><a NAME="E18:23_5"/><b>then </b>
( <font color="Maroon">c<sub>12</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>19</sub></font> or <font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E3:23_5"><i><font color="Green">E28</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/><a NAME="E19:23_5"/><b>then </b>
( <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>11</sub></font>,<font color="Maroon">c<sub>12</sub></font> or  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>9</sub></font>,<font color="Maroon">c<sub>10</sub></font>,<font color="Maroon">c<sub>7</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="txt" href="aff_3.html#E18:23"><i><font color="Green">E25</font></i></a>, <a class="ref" href="aff_1.html#T33">AFF_1:33</a>, <a class="ref" href="aff_1.html#T53">AFF_1:53</a></i>;<br/><a NAME="E20:23_5"/><b>then </b>
( <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>11</sub></font>,<font color="Maroon">c<sub>12</sub></font> or <font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>4</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E11:23"><i><font color="Green">E19</font></i></a>, <a class="ref" href="aff_1.html#T39">AFF_1:39</a></i>;<br/><b>hence </b><a NAME="E21:23_5"/>
<font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>11</sub></font>,<font color="Maroon">c<sub>12</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E6:23"><i><font color="Green">E14</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/></div><b>end;</b></div>
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_6"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:23_6"/>
not  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="aff_1.html#R4">//</a> <font color="Maroon">c<sub>19</sub></font>
 ;<br/><b>then consider </b><font color="Maroon">c<sub>20</sub></font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">c<sub>1</sub></font><b> such that </b><br/><a NAME="E3:23_6"/><i><font color="Green">E28</font></i>: 
( <font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font> &amp; <font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>19</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E17:23"><i><font color="Green">E24</font></i></a>, <a class="ref" href="aff_1.html#T72">AFF_1:72</a></i>;<br/><a NAME="E4:23_6"/>
not <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>20</sub></font> <a href="aff_1.html#R2">//</a> <font color="Maroon">c<sub>4</sub></font>
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_6_1"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_6_1"/>
<font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>20</sub></font> <a href="aff_1.html#R2">//</a> <font color="Maroon">c<sub>4</sub></font>
 ;<br/>

<a NAME="E2:23_6_1"/><b>then </b>
( <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>20</sub></font> <a href="aff_1.html#R2">//</a> <font color="Maroon">c<sub>4</sub></font> &amp; <font color="Maroon">c<sub>4</sub></font> <a href="aff_1.html#R4">//</a> <font color="Maroon">c<sub>3</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T58">AFF_1:58</a></i>;<br/>
<a NAME="E3:23_6_1"/><b>then </b>
<font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>20</sub></font> <a href="aff_1.html#R2">//</a> <font color="Maroon">c<sub>3</sub></font>
 
<b>by </b><i><a class="ref" href="aff_1.html#T57">AFF_1:57</a></i>;<br/>
<a NAME="E4:23_6_1"/><b>then </b>
<font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>3</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T37">AFF_1:37</a></i>;<br/>
<a NAME="E5:23_6_1"/><b>then </b>
( <font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>19</sub></font> or <font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>3</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E3:23_6"><i><font color="Green">E28</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/>
<a NAME="E6:23_6_1"/><b>then </b>
( <font color="Maroon">c<sub>8</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>11</sub></font> or <font color="Maroon">c<sub>19</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E6:23"><i><font color="Green">E14</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="txt" href="aff_3.html#E17:23"><i><font color="Green">E24</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>
<a NAME="E7:23_6_1"/><b>then </b>
(  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>5</sub></font> or  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="aff_1.html#R4">//</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E5:23"><i><font color="Green">E13</font></i></a>, <a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="ref" href="aff_1.html#T15">AFF_1:15</a></i>;<br/>
<a NAME="E8:23_6_1"/><b>then </b>
( <font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>3</sub></font> or  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E14:23"><i><font color="Green">E22</font></i></a>, <a class="ref" href="aff_1.html#T39">AFF_1:39</a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>
<b>hence </b><a NAME="E9:23_6_1"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/>


</div><b>end;</b></div><b>then consider </b><font color="Maroon">c<sub>21</sub></font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">c<sub>1</sub></font><b> such that </b><br/><a NAME="E6:23_6"/><i><font color="Green">E29</font></i>: 
( <font color="Maroon">c<sub>21</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>4</sub></font> &amp;  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>20</sub></font>,<font color="Maroon">c<sub>21</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="ref" href="aff_1.html#T73">AFF_1:73</a></i>;<br/><a NAME="E7:23_6"/><i><font color="Green">E30</font></i>: 
(  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>21</sub></font>,<font color="Maroon">c<sub>20</sub></font> &amp;  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font>,<font color="Maroon">c<sub>20</sub></font> &amp; <font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>11</sub></font>,<font color="Maroon">c<sub>20</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="txt" href="aff_3.html#E3:23_6"><i><font color="Green">E28</font></i></a>, <a class="txt" href="aff_3.html#E6:23_6"><i><font color="Green">E29</font></i></a>, <a class="ref" href="aff_1.html#T15">AFF_1:15</a>, <a class="ref" href="aff_1.html#T33">AFF_1:33</a>, <a class="ref" href="aff_1.html#T53">AFF_1:53</a></i>;<br/><a NAME="E8:23_6"/><i><font color="Green">E31</font></i>: 
not  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>21</sub></font>
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_6_2"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_6_2"/>
 <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>21</sub></font>
 ;<br/>

<a NAME="E2:23_6_2"/><b>then </b>
(  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>21</sub></font>,<font color="Maroon">c<sub>5</sub></font> &amp;  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>21</sub></font>,<font color="Maroon">c<sub>7</sub></font> )
 
<b>by </b><i><a class="ref" href="aff_1.html#T15">AFF_1:15</a>, <a class="ref" href="aff_1.html#T16">AFF_1:16</a></i>;<br/>
<a NAME="E3:23_6_2"/><b>then </b>
( <font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>21</sub></font> or  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>20</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E7:23_6"><i><font color="Green">E30</font></i></a>, <a class="ref" href="aff_1.html#T17">AFF_1:17</a></i>;<br/>
<a NAME="E4:23_6_2"/><b>then </b>
<font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E6:23"><i><font color="Green">E14</font></i></a>, <a class="txt" href="aff_3.html#E6:23_6"><i><font color="Green">E29</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/>
<a NAME="E5:23_6_2"/><b>then </b><i><font color="Green">E32</font></i>: 
( <font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>11</sub></font> or  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>19</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="txt" href="aff_3.html#E17:23"><i><font color="Green">E24</font></i></a>, <a class="txt" href="aff_3.html#E3:23_6"><i><font color="Green">E28</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/>
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_6_2_1"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:23_6_2_1"/>
<font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>11</sub></font>
 ;<br/><a NAME="E2:23_6_2_1"/><b>then </b>
( <font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>8</sub></font> or  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E3:23_6"><i><font color="Green">E28</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/><a NAME="E3:23_6_2_1"/><b>then </b>
(  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>5</sub></font> or <font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="ref" href="aff_1.html#T26">AFF_1:26</a>, <a class="ref" href="aff_1.html#T33">AFF_1:33</a></i>;<br/><a NAME="E4:23_6_2_1"/><b>then </b>
<font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>3</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E14:23"><i><font color="Green">E22</font></i></a>, <a class="ref" href="aff_1.html#T39">AFF_1:39</a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/><b>hence </b><a NAME="E5:23_6_2_1"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/></div><b>end;</b></div>
<a NAME="E7:23_6_2"/><b>then </b>
 <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>5</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E18:23"><i><font color="Green">E25</font></i></a>, <a class="txt" href="aff_3.html#E5:23_6_2"><i><font color="Green">E32</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>
<b>hence </b><a NAME="E8:23_6_2"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/>


</div><b>end;</b></div><a NAME="E9:23_6"/>
<font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">c<sub>20</sub></font>
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_6_3"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_6_3"/>
<font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>20</sub></font>
 ;<br/>

<a NAME="E2:23_6_3"/><b>then </b>
( <font color="Maroon">c<sub>11</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>8</sub></font> or  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R1">=</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="txt" href="aff_3.html#E3:23_6"><i><font color="Green">E28</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/>
<a NAME="E3:23_6_3"/><b>then </b>
(  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>5</sub></font> or <font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>8</sub></font>,<font color="Maroon">c<sub>6</sub></font> )
 
<b>by </b><i><a class="txt" href="aff_3.html#E13:23"><i><font color="Green">E21</font></i></a>, <a class="ref" href="aff_1.html#T26">AFF_1:26</a>, <a class="ref" href="aff_1.html#T33">AFF_1:33</a></i>;<br/>
<a NAME="E4:23_6_3"/><b>then </b>
<font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>3</sub></font>
 
<b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E14:23"><i><font color="Green">E22</font></i></a>, <a class="ref" href="aff_1.html#T39">AFF_1:39</a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/>
<b>hence </b><a NAME="E5:23_6_3"/>
contradiction
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/>


</div><b>end;</b></div><a NAME="E10:23_6"/><b>then </b>
<font color="Maroon">c<sub>6</sub></font>,<font color="Maroon">c<sub>10</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>21</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E1:23"><i><font color="Green">E9</font></i></a>, <a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E5:23"><i><font color="Green">E13</font></i></a>, <a class="txt" href="aff_3.html#E6:23_6"><i><font color="Green">E29</font></i></a>, <a class="txt" href="aff_3.html#E7:23_6"><i><font color="Green">E30</font></i></a>, <a class="txt" href="aff_3.html#E8:23_6"><i><font color="Green">E31</font></i></a>, <a class="ref" href="aff_3.html#D6" target="_self">Def6</a></i>;<br/><a NAME="E11:23_6"/><b>then </b>
<font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>21</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E5:23"><i><font color="Green">E13</font></i></a>, <a class="txt" href="aff_3.html#E7:23"><i><font color="Green">E15</font></i></a>, <a class="ref" href="aff_1.html#T14">AFF_1:14</a></i>;<br/><a NAME="E12:23_6"/><b>then </b>
 <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font>,<font color="Maroon">c<sub>21</sub></font>
 <b>by </b><i><a class="ref" href="aff_1.html#D1">AFF_1:def 1</a></i>;<br/><a NAME="E13:23_6"/><b>then </b>
<font color="Maroon">c<sub>21</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font>
 <b>by </b><i><a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/><a NAME="E14:23_6"/><b>then </b>
(  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>4</sub></font> or <font color="Maroon">c<sub>21</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>9</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E6:23_6"><i><font color="Green">E29</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/><a NAME="E15:23_6"/><b>then </b>
( <font color="Maroon">c<sub>5</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>4</sub></font> or  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font>,<font color="Maroon">c<sub>20</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E6:23_6"><i><font color="Green">E29</font></i></a>, <a class="ref" href="aff_1.html#T15">AFF_1:15</a>, <a class="ref" href="aff_1.html#T26">AFF_1:26</a></i>;<br/><a NAME="E16:23_6"/><b>then </b>
<font color="Maroon">c<sub>20</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a>, <a class="ref" href="aff_1.html#D2">AFF_1:def 2</a></i>;<br/><a NAME="E17:23_6"/><b>then </b>
( <font color="Maroon">c<sub>12</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>19</sub></font> or <font color="Maroon">c<sub>10</sub></font> <a href="hidden.html#R2">in</a>  <a href="aff_1.html#K2">Line</a> <font color="Maroon">c<sub>7</sub></font>,<font color="Maroon">c<sub>9</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E3:23_6"><i><font color="Green">E28</font></i></a>, <a class="ref" href="aff_1.html#T30">AFF_1:30</a></i>;<br/><a NAME="E18:23_6"/><b>then </b>
( <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>11</sub></font>,<font color="Maroon">c<sub>12</sub></font> or  <a href="aff_1.html#R1">LIN</a> <font color="Maroon">c<sub>9</sub></font>,<font color="Maroon">c<sub>10</sub></font>,<font color="Maroon">c<sub>7</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E8:23"><i><font color="Green">E16</font></i></a>, <a class="txt" href="aff_3.html#E16:23"><i><font color="Green">E23</font></i></a>, <a class="txt" href="aff_3.html#E18:23"><i><font color="Green">E25</font></i></a>, <a class="ref" href="aff_1.html#T33">AFF_1:33</a>, <a class="ref" href="aff_1.html#T53">AFF_1:53</a></i>;<br/><a NAME="E19:23_6"/><b>then </b>
( <font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>11</sub></font>,<font color="Maroon">c<sub>12</sub></font> or <font color="Maroon">c<sub>7</sub></font> <a href="hidden.html#R2">in</a> <font color="Maroon">c<sub>4</sub></font> )
 <b>by </b><i><a class="txt" href="aff_3.html#E2:23"><i><font color="Green">E10</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E11:23"><i><font color="Green">E19</font></i></a>, <a class="ref" href="aff_1.html#T39">AFF_1:39</a></i>;<br/><b>hence </b><a NAME="E20:23_6"/>
<font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>11</sub></font>,<font color="Maroon">c<sub>12</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E3:23"><i><font color="Green">E11</font></i></a>, <a class="txt" href="aff_3.html#E4:23"><i><font color="Green">E12</font></i></a>, <a class="txt" href="aff_3.html#E6:23"><i><font color="Green">E14</font></i></a>, <a class="ref" href="aff_1.html#T59">AFF_1:59</a></i>;<br/></div><b>end;</b></div>
<b>hence </b><a NAME="E22:23"/>
<font color="Maroon">c<sub>5</sub></font>,<font color="Maroon">c<sub>9</sub></font> <a href="analoaf.html#R2">//</a> <font color="Maroon">c<sub>11</sub></font>,<font color="Maroon">c<sub>12</sub></font>
 <b>by </b><i><a class="txt" href="aff_3.html#E19:23"><i><font color="Green">E26</font></i></a>, <a class="txt" href="aff_3.html#E20:23"><i><font color="Green">E27</font></i></a></i>;<br/>


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