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<b>set </b><font color="Maroon">c<sub>1</sub></font> =  <a href="group_1.html#G1" target="_self">HGrStr</a>(# <a href="numbers.html#K1">REAL</a> ,<a href="binop_2.html#K33">addreal</a>  #);<br/>
<a NAME="E1:11"/><i><font color="Green">E6</font></i>: 
for <font color="Olive">b<sub>1</sub></font>, <font color="Olive">b<sub>2</sub></font> being  <a href="struct_0.html#NM1">Element</a> of <a href="group_1.html#G1" target="_self">HGrStr</a>(# <a href="numbers.html#K1">REAL</a> ,<a href="binop_2.html#K33">addreal</a>  #)<br/>for <font color="Olive">b<sub>3</sub></font>, <font color="Olive">b<sub>4</sub></font> being  <a href="real_1.html#NM1">Real</a> st <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1">=</a> <font color="Olive">b<sub>3</sub></font> &amp; <font color="Olive">b<sub>2</sub></font> <a href="hidden.html#R1">=</a> <font color="Olive">b<sub>4</sub></font> holds <br/><font color="Olive">b<sub>1</sub></font> <a href="group_1.html#K1" target="_self">*</a> <font color="Olive">b<sub>2</sub></font> <a href="hidden.html#R1">=</a> <font color="Olive">b<sub>3</sub></font> <a href="binop_2.html#K9">+</a> <font color="Olive">b<sub>4</sub></font>
 
<b>by </b><i><a class="ref" href="binop_2.html#D9">BINOP_2:def 9</a></i>;<br/>
<b>thus </b><a NAME="E2:11"/>
for <font color="Olive">b<sub>1</sub></font>, <font color="Olive">b<sub>2</sub></font>, <font color="Olive">b<sub>3</sub></font> being  <a href="struct_0.html#NM1">Element</a> of <a href="group_1.html#G1" target="_self">HGrStr</a>(# <a href="numbers.html#K1">REAL</a> ,<a href="binop_2.html#K33">addreal</a>  #) holds <span class="p1">(<span class="default"><font color="Olive">b<sub>1</sub></font> <a href="group_1.html#K1" target="_self">*</a> <font color="Olive">b<sub>2</sub></font></span>)</span> <a href="group_1.html#K1" target="_self">*</a> <font color="Olive">b<sub>3</sub></font> <a href="hidden.html#R1">=</a> <font color="Olive">b<sub>1</sub></font> <a href="group_1.html#K1" target="_self">*</a> <span class="p1">(<span class="default"><font color="Olive">b<sub>2</sub></font> <a href="group_1.html#K1" target="_self">*</a> <font color="Olive">b<sub>3</sub></font></span>)</span>
  <i><font color="Red">:: according to </font></i><a class="ref" href="group_1.html#D4" target="_self">GROUP_1:def 4</a><div><a class="txt" onclick="hs2(this)" href="javascript:()" title="11_1"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">c<sub>2</sub></font>, <font color="Maroon">c<sub>3</sub></font>, <font color="Maroon">c<sub>4</sub></font> be   <a href="struct_0.html#NM1">Element</a> of <a href="group_1.html#G1" target="_self">HGrStr</a>(# <a href="numbers.html#K1">REAL</a> ,<a href="binop_2.html#K33">addreal</a>  #);<br/>

<b>reconsider </b><font color="Maroon">c<sub>5</sub></font> = <font color="Maroon">c<sub>2</sub></font>, <font color="Maroon">c<sub>6</sub></font> = <font color="Maroon">c<sub>3</sub></font>, <font color="Maroon">c<sub>7</sub></font> = <font color="Maroon">c<sub>4</sub></font> as   <a href="real_1.html#NM1">Real</a> ;<br/>
<a NAME="E2:11_1"/><i><font color="Green">E7</font></i>: 
<font color="Maroon">c<sub>2</sub></font> <a href="group_1.html#K1" target="_self">*</a> <font color="Maroon">c<sub>3</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>5</sub></font> <a href="binop_2.html#K9">+</a> <font color="Maroon">c<sub>6</sub></font>
 
<b>by </b><i><a class="txt" href="group_1.html#E1:11"><i><font color="Green">E6</font></i></a></i>;<br/>
<a NAME="E3:11_1"/><i><font color="Green">E8</font></i>: 
<font color="Maroon">c<sub>3</sub></font> <a href="group_1.html#K1" target="_self">*</a> <font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>6</sub></font> <a href="binop_2.html#K9">+</a> <font color="Maroon">c<sub>7</sub></font>
 
<b>by </b><i><a class="txt" href="group_1.html#E1:11"><i><font color="Green">E6</font></i></a></i>;<br/>
<b>thus </b><span class="p1">(<span class="default"><font color="Maroon">c<sub>2</sub></font> <a href="group_1.html#K1" target="_self">*</a> <font color="Maroon">c<sub>3</sub></font></span>)</span> <a href="group_1.html#K1" target="_self">*</a> <font color="Maroon">c<sub>4</sub></font> = 
<span class="p1">(<span class="default"><font color="Maroon">c<sub>5</sub></font> <a href="binop_2.html#K9">+</a> <font color="Maroon">c<sub>6</sub></font></span>)</span> <a href="binop_2.html#K9">+</a> <font color="Maroon">c<sub>7</sub></font>
<b>by </b><i><a class="txt" href="group_1.html#E1:11"><i><font color="Green">E6</font></i></a>, <a class="txt" href="group_1.html#E2:11_1"><i><font color="Green">E7</font></i></a></i>
<br/>.= 
<font color="Maroon">c<sub>5</sub></font> <a href="binop_2.html#K9">+</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>6</sub></font> <a href="binop_2.html#K9">+</a> <font color="Maroon">c<sub>7</sub></font></span>)</span>

<br/>.= 
<font color="Maroon">c<sub>2</sub></font> <a href="group_1.html#K1" target="_self">*</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>3</sub></font> <a href="group_1.html#K1" target="_self">*</a> <font color="Maroon">c<sub>4</sub></font></span>)</span>
<b>by </b><i><a class="txt" href="group_1.html#E1:11"><i><font color="Green">E6</font></i></a>, <a class="txt" href="group_1.html#E3:11_1"><i><font color="Green">E8</font></i></a></i>
;<br/>


</div><b>end;</b></div>

<b>reconsider </b><font color="Maroon">c<sub>2</sub></font> = 0 as   <a href="struct_0.html#NM1">Element</a> of <a href="group_1.html#G1" target="_self">HGrStr</a>(# <a href="numbers.html#K1">REAL</a> ,<a href="binop_2.html#K33">addreal</a>  #) ;<br/>
<b>take </b>
<font color="Maroon">c<sub>2</sub></font>
; <i><font color="Red">:: according to </font></i><a class="ref" href="group_1.html#D3" target="_self">GROUP_1:def 3</a><br/>

<b>let </b><font color="Maroon">c<sub>3</sub></font> be   <a href="struct_0.html#NM1">Element</a> of <a href="group_1.html#G1" target="_self">HGrStr</a>(# <a href="numbers.html#K1">REAL</a> ,<a href="binop_2.html#K33">addreal</a>  #);<br/>

<b>reconsider </b><font color="Maroon">c<sub>4</sub></font> = <font color="Maroon">c<sub>3</sub></font> as   <a href="real_1.html#NM1">Real</a> ;<br/>
<b>thus </b><font color="Maroon">c<sub>3</sub></font> <a href="group_1.html#K1" target="_self">*</a> <font color="Maroon">c<sub>2</sub></font> = 
<font color="Maroon">c<sub>4</sub></font> <a href="binop_2.html#K9">+</a> 0
<b>by </b><i><a class="txt" href="group_1.html#E1:11"><i><font color="Green">E6</font></i></a></i>
<br/>.= 
<font color="Maroon">c<sub>3</sub></font>

;<br/>

<b>thus </b><font color="Maroon">c<sub>2</sub></font> <a href="group_1.html#K1" target="_self">*</a> <font color="Maroon">c<sub>3</sub></font> = 
0 <a href="binop_2.html#K9">+</a> <font color="Maroon">c<sub>4</sub></font>
<b>by </b><i><a class="txt" href="group_1.html#E1:11"><i><font color="Green">E6</font></i></a></i>
<br/>.= 
<font color="Maroon">c<sub>3</sub></font>

;<br/>

<b>reconsider </b><font color="Maroon">c<sub>5</sub></font> =  <a href="binop_2.html#K7">-</a> <font color="Maroon">c<sub>4</sub></font> as   <a href="struct_0.html#NM1">Element</a> of <a href="group_1.html#G1" target="_self">HGrStr</a>(# <a href="numbers.html#K1">REAL</a> ,<a href="binop_2.html#K33">addreal</a>  #) ;<br/>
<b>take </b>
<font color="Maroon">c<sub>5</sub></font>
;<br/>

<b>thus </b><font color="Maroon">c<sub>3</sub></font> <a href="group_1.html#K1" target="_self">*</a> <font color="Maroon">c<sub>5</sub></font> = 
<font color="Maroon">c<sub>4</sub></font> <a href="binop_2.html#K9">+</a> <span class="p1">(<span class="default"><a href="binop_2.html#K7">-</a> <font color="Maroon">c<sub>4</sub></font></span>)</span>
<b>by </b><i><a class="txt" href="group_1.html#E1:11"><i><font color="Green">E6</font></i></a></i>
<br/>.= 
<font color="Maroon">c<sub>2</sub></font>

;<br/>

<b>thus </b><font color="Maroon">c<sub>5</sub></font> <a href="group_1.html#K1" target="_self">*</a> <font color="Maroon">c<sub>3</sub></font> = 
<span class="p1">(<span class="default"><a href="binop_2.html#K7">-</a> <font color="Maroon">c<sub>4</sub></font></span>)</span> <a href="binop_2.html#K9">+</a> <font color="Maroon">c<sub>4</sub></font>
<b>by </b><i><a class="txt" href="group_1.html#E1:11"><i><font color="Green">E6</font></i></a></i>
<br/>.= 
<font color="Maroon">c<sub>2</sub></font>

;<br/>


</div>
