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<b>let </b><font color="Maroon">CLSP</font> be  <a href="collsp.html#V4" target="_self">proper</a> <a href="collsp.html#NM2">CollSp</a>;<br/><b>let </b><font color="Maroon">p</font> be   <a href="pre_topc.html#NM2">Point</a> of <font color="Maroon">CLSP</font>;<br/><b>let </b><font color="Maroon">q</font> be   <a href="pre_topc.html#NM2">Point</a> of <font color="Maroon">CLSP</font>;<br/>





<b>assume </b><a NAME="E1:28"/><i><font color="Green">E19</font></i>: 
<font color="Maroon">p</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">q</font>
 ;<br/>

<b>consider </b><font color="Maroon">a</font> being   <a href="pre_topc.html#NM2">Point</a> of <font color="Maroon">CLSP</font>, <font color="Maroon">b</font> being   <a href="pre_topc.html#NM2">Point</a> of <font color="Maroon">CLSP</font>, <font color="Maroon">c</font> being   <a href="pre_topc.html#NM2">Point</a> of <font color="Maroon">CLSP</font><b> such that </b><br/><a NAME="E3:28"/><i><font color="Green">E20</font></i>: 
not <font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font> <a href="collsp.html#R1" target="_self">is_collinear</a> 
 <b>by </b><i/>;<br/>
<a NAME="E4:28"/>
(  not <font color="Maroon">p</font>,<font color="Maroon">q</font>,<font color="Maroon">a</font> <a href="collsp.html#R1" target="_self">is_collinear</a>  or  not <font color="Maroon">p</font>,<font color="Maroon">q</font>,<font color="Maroon">b</font> <a href="collsp.html#R1" target="_self">is_collinear</a>  or  not <font color="Maroon">p</font>,<font color="Maroon">q</font>,<font color="Maroon">c</font> <a href="collsp.html#R1" target="_self">is_collinear</a>  )
 
<b>by </b><i>, , </i>;<br/>
<b>hence </b><a NAME="E5:28"/>
not for <font color="Olive">r</font> being  <a href="pre_topc.html#NM2">Point</a> of <font color="Maroon">CLSP</font> holds  <font color="Maroon">p</font>,<font color="Maroon">q</font>,<font color="Olive">r</font> <a href="collsp.html#R1" target="_self">is_collinear</a> 
 ;<br/>


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