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<b>let </b><font color="Maroon">S</font> be   <a href="analoaf.html#NM1">OAffinSpace</a>;<br/><b>let </b><font color="Maroon">x</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">S</font>;<br/><b>let </b><font color="Maroon">y</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">S</font>;<br/><b>let </b><font color="Maroon">z</font> be   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">S</font>;<br/>







<a NAME="E1:12"/>
( <font color="Maroon">x</font>,<font color="Maroon">y</font> <a href="analoaf.html#R2">//</a> <font color="Maroon">x</font>,<font color="Maroon">z</font> iff ( <font color="Maroon">x</font>,<font color="Maroon">y</font> <a href="analoaf.html#R2">//</a> <font color="Maroon">y</font>,<font color="Maroon">z</font> or <font color="Maroon">x</font>,<font color="Maroon">z</font> <a href="analoaf.html#R2">//</a> <font color="Maroon">z</font>,<font color="Maroon">y</font> ) )
 
<b>by </b><i/>;<br/>
<b>hence </b><a NAME="E2:12"/>
( <font color="Maroon">x</font>,<font color="Maroon">y</font> <a href="analoaf.html#R2">//</a> <font color="Maroon">x</font>,<font color="Maroon">z</font> iff (  <a href="diraf.html#R1" target="_self">Mid</a> <font color="Maroon">x</font>,<font color="Maroon">y</font>,<font color="Maroon">z</font> or  <a href="diraf.html#R1" target="_self">Mid</a> <font color="Maroon">x</font>,<font color="Maroon">z</font>,<font color="Maroon">y</font> ) )
 <b>by </b><i/>;<br/>


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