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<b>thus </b><a NAME="E1:73_1_1"/>
( <font color="Maroon">c<sub>1</sub></font> is <a href="robbins1.html#V5" target="_self">Huntington</a> implies 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 <font color="Maroon">c<sub>1</sub></font> holds <span class="p1">(<span class="default"><a href="robbins1.html#NK11" target="_self">-</a> <span class="p2">(<span class="default"><span class="p3">(<span class="default"><a href="robbins1.html#NK11" target="_self">-</a> <font color="Olive">b<sub>1</sub></font></span>)</span> <a href="robbins1.html#K5" target="_self">+</a> <span class="p3">(<span class="default"><a href="robbins1.html#NK11" target="_self">-</a> <font color="Olive">b<sub>2</sub></font></span>)</span></span>)</span></span>)</span> <a href="robbins1.html#K5" target="_self">+</a> <span class="p1">(<span class="default"><a href="robbins1.html#NK11" target="_self">-</a> <span class="p2">(<span class="default"><font color="Olive">b<sub>1</sub></font> <a href="robbins1.html#K5" target="_self">+</a> <span class="p3">(<span class="default"><a href="robbins1.html#NK11" target="_self">-</a> <font color="Olive">b<sub>2</sub></font></span>)</span></span>)</span></span>)</span> <a href="hidden.html#R1">=</a> <font color="Olive">b<sub>2</sub></font> )
 <b>by </b><i><a class="ref" href="robbins1.html#D6" target="_self">Def6</a></i>;<br/>

<b>assume </b><a NAME="E2:73_1_1"/><i><font color="Green">E40</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 <font color="Maroon">c<sub>1</sub></font> holds <span class="p1">(<span class="default"><a href="robbins1.html#NK11" target="_self">-</a> <span class="p2">(<span class="default"><span class="p3">(<span class="default"><a href="robbins1.html#NK11" target="_self">-</a> <font color="Olive">b<sub>1</sub></font></span>)</span> <a href="robbins1.html#K5" target="_self">+</a> <span class="p3">(<span class="default"><a href="robbins1.html#NK11" target="_self">-</a> <font color="Olive">b<sub>2</sub></font></span>)</span></span>)</span></span>)</span> <a href="robbins1.html#K5" target="_self">+</a> <span class="p1">(<span class="default"><a href="robbins1.html#NK11" target="_self">-</a> <span class="p2">(<span class="default"><font color="Olive">b<sub>1</sub></font> <a href="robbins1.html#K5" target="_self">+</a> <span class="p3">(<span class="default"><a href="robbins1.html#NK11" target="_self">-</a> <font color="Olive">b<sub>2</sub></font></span>)</span></span>)</span></span>)</span> <a href="hidden.html#R1">=</a> <font color="Olive">b<sub>2</sub></font>
 ;<br/>

<b>let </b><font color="Maroon">c<sub>2</sub></font>, <font color="Maroon">c<sub>3</sub></font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">c<sub>1</sub></font>; <i><font color="Red">:: according to </font></i><a class="ref" href="robbins1.html#D6" target="_self">ROBBINS1:def 6</a><br/>

<a NAME="E3:73_1_1"/>
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><font color="Maroon">c<sub>2</sub></font> <a href="robbins1.html#K3" target="_self">`</a> </span>)</span> <a href="robbins1.html#K5" target="_self">+</a> <span class="p3">(<span class="default"><font color="Maroon">c<sub>3</sub></font> <a href="robbins1.html#K3" target="_self">`</a> </span>)</span></span>)</span> <a href="robbins1.html#K3" target="_self">`</a> </span>)</span> <a href="robbins1.html#K5" target="_self">+</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><font color="Maroon">c<sub>2</sub></font> <a href="robbins1.html#K3" target="_self">`</a> </span>)</span> <a href="robbins1.html#K5" target="_self">+</a> <font color="Maroon">c<sub>3</sub></font></span>)</span> <a href="robbins1.html#K3" target="_self">`</a> </span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>2</sub></font>
 
<b>by </b><i><a class="txt" href="robbins1.html#E2:73_1_1"><i><font color="Green">E40</font></i></a></i>;<br/>
<b>hence </b><a NAME="E4:73_1_1"/>
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><font color="Maroon">c<sub>2</sub></font> <a href="robbins1.html#K3" target="_self">`</a> </span>)</span> <a href="robbins1.html#NK4" target="_self">+</a> <span class="p3">(<span class="default"><font color="Maroon">c<sub>3</sub></font> <a href="robbins1.html#K3" target="_self">`</a> </span>)</span></span>)</span> <a href="robbins1.html#K3" target="_self">`</a> </span>)</span> <a href="robbins1.html#NK4" target="_self">+</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><font color="Maroon">c<sub>2</sub></font> <a href="robbins1.html#K3" target="_self">`</a> </span>)</span> <a href="robbins1.html#NK4" target="_self">+</a> <font color="Maroon">c<sub>3</sub></font></span>)</span> <a href="robbins1.html#K3" target="_self">`</a> </span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>2</sub></font>
 ;<br/>


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