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<b>let </b><font color="Maroon">M</font> be   <a href="midsp_1.html#NM1">MidSp</a>;<br/><b>let </b><font color="Maroon">u</font> be    <a href="midsp_1.html#M1" target="_self">Vector</a> of <font color="Maroon">M</font>;<br/><b>let </b><font color="Maroon">v</font> be    <a href="midsp_1.html#M1" target="_self">Vector</a> of <font color="Maroon">M</font>;<br/>





<b>consider </b><font color="Maroon">a</font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">M</font>;<br/>
<b>consider </b><font color="Maroon">b</font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">M</font><b> such that </b><br/><a NAME="E3:57"/><i><font color="Green">E37</font></i>: 
<font color="Maroon">u</font> <a href="hidden.html#R1">=</a>  <a href="midsp_1.html#K11" target="_self">vect</a> <font color="Maroon">a</font>,<font color="Maroon">b</font>
 <b>by </b><i/>;<br/>
<b>consider </b><font color="Maroon">c</font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">M</font><b> such that </b><br/><a NAME="E5:57"/><i><font color="Green">E38</font></i>: 
<font color="Maroon">v</font> <a href="hidden.html#R1">=</a>  <a href="midsp_1.html#K11" target="_self">vect</a> <font color="Maroon">b</font>,<font color="Maroon">c</font>
 <b>by </b><i/>;<br/>
<b>consider </b><font color="Maroon">d</font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">M</font><b> such that </b><br/><a NAME="E7:57"/><i><font color="Green">E63</font></i>: 
<font color="Maroon">v</font> <a href="hidden.html#R1">=</a>  <a href="midsp_1.html#K11" target="_self">vect</a> <font color="Maroon">a</font>,<font color="Maroon">d</font>
 <b>by </b><i/>;<br/>
<b>consider </b><font color="Maroon">c'</font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">M</font><b> such that </b><br/><a NAME="E9:57"/><i><font color="Green">E76</font></i>: 
<font color="Maroon">u</font> <a href="hidden.html#R1">=</a>  <a href="midsp_1.html#K11" target="_self">vect</a> <font color="Maroon">d</font>,<font color="Maroon">c'</font>
 <b>by </b><i/>;<br/>
<i><font color="Green">E77</font></i>: <font color="Maroon">a</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">c'</font> = 
<font color="Maroon">b</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">d</font>
<b>by </b><i><a class="ref" href="midsp_1.html#T23" target="_self">Th23</a>, <a class="ref" href="midsp_1.html#T26" target="_self">Th26</a>, <a class="ref" href="midsp_1.html#T16" target="_self">Th16</a></i>
<br/>.= 
<font color="Maroon">a</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">c</font>
<b>by </b><i><a class="ref" href="midsp_1.html#T24" target="_self">Th24</a>, <a class="ref" href="midsp_1.html#T25" target="_self">Th25</a>, <a class="ref" href="midsp_1.html#T16" target="_self">Th16</a></i>
;<br/>
<font color="Maroon">u</font> <a href="midsp_1.html#K10" target="_self">+</a> <font color="Maroon">v</font> = 
 <a href="midsp_1.html#K11" target="_self">vect</a> <font color="Maroon">a</font>,<font color="Maroon">c</font>
<b>by </b><i><a class="ref" href="midsp_1.html#T23" target="_self">Th23</a>, <a class="ref" href="midsp_1.html#T24" target="_self">Th24</a>, <a class="txt" href="midsp_1.html#E3:57"><i><font color="Green">E37</font></i></a></i>
<br/>.= 
 <a href="midsp_1.html#K11" target="_self">vect</a> <font color="Maroon">a</font>,<font color="Maroon">c'</font>
<b>by </b><i><a class="ref" href="midsp_1.html#T27" target="_self">Th27</a>, </i>
<br/>.= 
<font color="Maroon">v</font> <a href="midsp_1.html#K10" target="_self">+</a> <font color="Maroon">u</font>
<b>by </b><i><a class="ref" href="midsp_1.html#T25" target="_self">Th25</a>, <a class="ref" href="midsp_1.html#T26" target="_self">Th26</a>, <a class="txt" href="midsp_1.html#E3:57"><i><font color="Green">E37</font></i></a></i>
;<br/>
<b>hence </b><a NAME="E12:57"/>
<font color="Maroon">u</font> <a href="midsp_1.html#K10" target="_self">+</a> <font color="Maroon">v</font> <a href="hidden.html#R1">=</a> <font color="Maroon">v</font> <a href="midsp_1.html#K10" target="_self">+</a> <font color="Maroon">u</font>
 ;<br/>


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