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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">x</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">M</font>;<br/><b>let </b><font color="Maroon">y</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">M</font>;<br/><b>let </b><font color="Maroon">a</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">M</font>;<br/><b>let </b><font color="Maroon">b</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">M</font>;<br/><b>let </b><font color="Maroon">c</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">M</font>;<br/><b>let </b><font color="Maroon">d</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">M</font>;<br/>













<b>assume </b><a NAME="E1:24"/><i><font color="Green">E37</font></i>: 
<font color="Maroon">x</font>,<font color="Maroon">y</font> <a href="midsp_1.html#R1" target="_self">@@</a> <font color="Maroon">a</font>,<font color="Maroon">b</font>
 ;<br/>

<b>assume </b><a NAME="E2:24"/><i><font color="Green">E38</font></i>: 
<font color="Maroon">x</font>,<font color="Maroon">y</font> <a href="midsp_1.html#R1" target="_self">@@</a> <font color="Maroon">c</font>,<font color="Maroon">d</font>
 ;<br/>

<span class="p1">(<span class="default"><font color="Maroon">y</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">x</font></span>)</span> <a href="midsp_1.html#K4" target="_self">@</a> <span class="p1">(<span class="default"><font color="Maroon">a</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">d</font></span>)</span> = 
<span class="p1">(<span class="default"><font color="Maroon">y</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">a</font></span>)</span> <a href="midsp_1.html#K4" target="_self">@</a> <span class="p1">(<span class="default"><font color="Maroon">x</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">d</font></span>)</span>
<b>by </b><i/>
<br/>.= 
<span class="p1">(<span class="default"><font color="Maroon">x</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">b</font></span>)</span> <a href="midsp_1.html#K4" target="_self">@</a> <span class="p1">(<span class="default"><font color="Maroon">x</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">d</font></span>)</span>
<b>by </b><i>, </i>
<br/>.= 
<span class="p1">(<span class="default"><font color="Maroon">x</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">b</font></span>)</span> <a href="midsp_1.html#K4" target="_self">@</a> <span class="p1">(<span class="default"><font color="Maroon">y</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">c</font></span>)</span>
<b>by </b><i>, </i>
<br/>.= 
<span class="p1">(<span class="default"><font color="Maroon">y</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">x</font></span>)</span> <a href="midsp_1.html#K4" target="_self">@</a> <span class="p1">(<span class="default"><font color="Maroon">b</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">c</font></span>)</span>
<b>by </b><i/>
;<br/>
<b>hence </b><a NAME="E4:24"/>
<font color="Maroon">a</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> <font color="Maroon">b</font> <a href="midsp_1.html#K4" target="_self">@</a> <font color="Maroon">c</font>
 <b>by </b><i/>; <i><font color="Red">:: according to </font></i><a class="ref" href="midsp_1.html#D5" target="_self">MIDSP_1:def 5</a><br/>


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