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<div class="add">

<b>let </b><font color="Maroon">c<sub>1</sub></font>, <font color="Maroon">c<sub>2</sub></font> be   <a href="nat_1.html#NM1">Nat</a>;<br/><b>let </b><font color="Maroon">c<sub>3</sub></font> be   <a href="binarith.html#NM1">Tuple</a> of <span class="p1">(<span class="default"><font color="Maroon">c<sub>1</sub></font> <a href="nat_1.html#K1">+</a> 2</span>)</span>,<span class="p1">(<span class="default"><font color="Maroon">c<sub>2</sub></font> <a href="radix_1.html#K3">-SD</a> </span>)</span>;<br/>



<b>assume </b><a NAME="E1:27"/><i><font color="Green">E24</font></i>: 
( <font color="Maroon">c<sub>1</sub></font> <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> 1 &amp; <font color="Maroon">c<sub>2</sub></font> <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> 2 )
 ;<br/>

<a NAME="E2:27"/><i><font color="Green">E25</font></i>: 
<font color="Maroon">c<sub>1</sub></font> <a href="nat_1.html#K1">+</a> 2 <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> 1
 
<b>by </b><i><a class="ref" href="nat_1.html#T37">NAT_1:37</a></i>;<br/>
<a NAME="E3:27"/>
for <font color="Olive">b<sub>1</sub></font> being  <a href="nat_1.html#NM1">Nat</a> holds <br/>(  not <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R2">in</a>  <a href="finseq_1.html#K2">Seg</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>1</sub></font> <a href="nat_1.html#K1">+</a> 2</span>)</span> or (  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K2" target="_self">M0</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1">=</a>  <a href="radix_1.html#K4">DigA</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Olive">b<sub>1</sub></font> &amp;  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K8" target="_self">Mmask</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1">=</a> 0 ) or (  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K8" target="_self">Mmask</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1">=</a>  <a href="radix_1.html#K4">DigA</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Olive">b<sub>1</sub></font> &amp;  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K2" target="_self">M0</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<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="27_1"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">c<sub>4</sub></font> be   <a href="nat_1.html#NM1">Nat</a>;<br/>

<b>assume </b><a NAME="E1:27_1"/><i><font color="Green">E26</font></i>: 
<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R2">in</a>  <a href="finseq_1.html#K2">Seg</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>1</sub></font> <a href="nat_1.html#K1">+</a> 2</span>)</span>
 ;<br/>

<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="27_1_1"><b>now </b></a><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="27_1_1_1"><b>per </b></a><a class="txt" onclick="hs(this)" href="javascript:()"><b>cases </b></a><span class="hide"><a NAME="E1:27_1_1_1"/>
( <font color="Maroon">c<sub>4</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Maroon">c<sub>1</sub></font> or <font color="Maroon">c<sub>4</sub></font> <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> <font color="Maroon">c<sub>1</sub></font> )
 </span>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="27_1_1_1_1"><b>suppose </b></a><a NAME="E1:27_1_1_1_1"/><i><font color="Green">E27</font></i>: 
<font color="Maroon">c<sub>4</sub></font> <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Maroon">c<sub>1</sub></font>
 ;<br/><div class="add"><i><font color="Green">E28</font></i>:  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K8" target="_self">Mmask</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> = 
 <a href="radix_6.html#K7" target="_self">MmaskDigit</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font>
<b>by </b><i><a class="txt" href="radix_6.html#E1:27_1"><i><font color="Green">E26</font></i></a>, <a class="ref" href="radix_6.html#D9" target="_self">Def9</a></i>
<br/>.= 
<font color="Maroon">c<sub>3</sub></font> <a href="funct_1.html#K1">.</a> <font color="Maroon">c<sub>4</sub></font>
<b>by </b><i><a class="txt" href="radix_6.html#E1:27_1"><i><font color="Green">E26</font></i></a>, <a class="txt" href="radix_6.html#E1:27_1_1_1_1"><i><font color="Green">E27</font></i></a>, <a class="ref" href="radix_6.html#D8" target="_self">Def8</a></i>
<br/>.= 
 <a href="radix_1.html#K4">DigA</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font>
<b>by </b><i><a class="txt" href="radix_6.html#E1:27_1"><i><font color="Green">E26</font></i></a>, <a class="ref" href="radix_1.html#D3">RADIX_1:def 3</a></i>
;<br/> <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K2" target="_self">M0</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> = 
 <a href="radix_6.html#K1" target="_self">M0Digit</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font>
<b>by </b><i><a class="txt" href="radix_6.html#E1:27_1"><i><font color="Green">E26</font></i></a>, <a class="ref" href="radix_6.html#D2" target="_self">Def2</a></i>
<br/>.= 
0
<b>by </b><i><a class="txt" href="radix_6.html#E1:27_1"><i><font color="Green">E26</font></i></a>, <a class="txt" href="radix_6.html#E1:27_1_1_1_1"><i><font color="Green">E27</font></i></a>, <a class="ref" href="radix_6.html#D1" target="_self">Def1</a></i>
;<br/><b>hence </b><a NAME="E4:27_1_1_1_1"/>
( (  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K2" target="_self">M0</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a>  <a href="radix_1.html#K4">DigA</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font> &amp;  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K8" target="_self">Mmask</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a> 0 ) or (  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K8" target="_self">Mmask</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a>  <a href="radix_1.html#K4">DigA</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font> &amp;  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K2" target="_self">M0</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a> 0 ) )
 <b>by </b><i><a class="txt" href="radix_6.html#E2:27_1_1_1_1"><i><font color="Green">E28</font></i></a></i>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="27_1_1_1_2"><b>suppose </b></a><a NAME="E1:27_1_1_1_2"/><i><font color="Green">E27</font></i>: 
<font color="Maroon">c<sub>4</sub></font> <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> <font color="Maroon">c<sub>1</sub></font>
 ;<br/><div class="add"><i><font color="Green">E28</font></i>:  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K8" target="_self">Mmask</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> = 
 <a href="radix_6.html#K7" target="_self">MmaskDigit</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font>
<b>by </b><i><a class="txt" href="radix_6.html#E1:27_1"><i><font color="Green">E26</font></i></a>, <a class="ref" href="radix_6.html#D9" target="_self">Def9</a></i>
<br/>.= 
0
<b>by </b><i><a class="txt" href="radix_6.html#E1:27_1"><i><font color="Green">E26</font></i></a>, <a class="txt" href="radix_6.html#E1:27_1_1_1_2"><i><font color="Green">E27</font></i></a>, <a class="ref" href="radix_6.html#D8" target="_self">Def8</a></i>
;<br/> <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K2" target="_self">M0</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> = 
 <a href="radix_6.html#K1" target="_self">M0Digit</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font>
<b>by </b><i><a class="txt" href="radix_6.html#E1:27_1"><i><font color="Green">E26</font></i></a>, <a class="ref" href="radix_6.html#D2" target="_self">Def2</a></i>
<br/>.= 
<font color="Maroon">c<sub>3</sub></font> <a href="funct_1.html#K1">.</a> <font color="Maroon">c<sub>4</sub></font>
<b>by </b><i><a class="txt" href="radix_6.html#E1:27_1"><i><font color="Green">E26</font></i></a>, <a class="txt" href="radix_6.html#E1:27_1_1_1_2"><i><font color="Green">E27</font></i></a>, <a class="ref" href="radix_6.html#D1" target="_self">Def1</a></i>
<br/>.= 
 <a href="radix_1.html#K4">DigA</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font>
<b>by </b><i><a class="txt" href="radix_6.html#E1:27_1"><i><font color="Green">E26</font></i></a>, <a class="ref" href="radix_1.html#D3">RADIX_1:def 3</a></i>
;<br/><b>hence </b><a NAME="E4:27_1_1_1_2"/>
( (  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K2" target="_self">M0</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a>  <a href="radix_1.html#K4">DigA</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font> &amp;  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K8" target="_self">Mmask</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a> 0 ) or (  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K8" target="_self">Mmask</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a>  <a href="radix_1.html#K4">DigA</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font> &amp;  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K2" target="_self">M0</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a> 0 ) )
 <b>by </b><i><a class="txt" href="radix_6.html#E2:27_1_1_1_2"><i><font color="Green">E28</font></i></a></i>;<br/></div><b>end;</b></div></div><b>end;</b></div></div><b>end;</b></div>
<b>hence </b><a NAME="E3:27_1"/>
( (  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K2" target="_self">M0</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a>  <a href="radix_1.html#K4">DigA</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font> &amp;  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K8" target="_self">Mmask</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a> 0 ) or (  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K8" target="_self">Mmask</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a>  <a href="radix_1.html#K4">DigA</a> <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font> &amp;  <a href="radix_1.html#K4">DigA</a> <span class="p1">(<span class="default"><a href="radix_6.html#K2" target="_self">M0</a> <font color="Maroon">c<sub>3</sub></font></span>)</span>,<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a> 0 ) )
 ;<br/>


</div><b>end;</b></div>
<b>hence </b><a NAME="E4:27"/>
<span class="p1">(<span class="default"><a href="radix_1.html#K8">SDDec</a> <span class="p2">(<span class="default"><a href="radix_6.html#K2" target="_self">M0</a> <font color="Maroon">c<sub>3</sub></font></span>)</span></span>)</span> <a href="xcmplx_0.html#K2">+</a> <span class="p1">(<span class="default"><a href="radix_1.html#K8">SDDec</a> <span class="p2">(<span class="default"><a href="radix_6.html#K8" target="_self">Mmask</a> <font color="Maroon">c<sub>3</sub></font></span>)</span></span>)</span> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><a href="radix_1.html#K8">SDDec</a> <font color="Maroon">c<sub>3</sub></font></span>)</span> <a href="xcmplx_0.html#K2">+</a> <span class="p1">(<span class="default"><a href="radix_1.html#K8">SDDec</a> <span class="p2">(<span class="default"><a href="radix_1.html#K10">DecSD</a> 0,<span class="p3">(<span class="default"><font color="Maroon">c<sub>1</sub></font> <a href="nat_1.html#K1">+</a> 2</span>)</span>,<font color="Maroon">c<sub>2</sub></font></span>)</span></span>)</span>
 <b>by </b><i><a class="txt" href="radix_6.html#E1:27"><i><font color="Green">E24</font></i></a>, <a class="txt" href="radix_6.html#E2:27"><i><font color="Green">E25</font></i></a>, <a class="ref" href="radix_5.html#T15">RADIX_5:15</a></i>;<br/>


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