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<b>let </b><font color="Maroon" title="c1">SAS</font> be   <a href="semi_af1.html#NM1" title="SEMI_AF1:NM.1">Semi_Affine_Space</a>;<br/><b>let </b><font color="Maroon" title="c2">o</font> be   <a href="struct_0.html#NM1" title="STRUCT_0:NM.1">Element</a> of <font color="Maroon" title="c1">SAS</font>;<br/>



<a NAME="E1:88"/>
 <a href="semi_af1.html#K1" title="SEMI_AF1:func.1">sum</a> <font color="Maroon" title="c2">o</font>,<span class="p1">(<span class="default"><a href="semi_af1.html#K2" title="SEMI_AF1:func.2">opposite</a> <font color="Maroon" title="c2">o</font>,<font color="Maroon" title="c2">o</font></span>)</span>,<font color="Maroon" title="c2">o</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">o</font>
 
<b>by </b><i><a class="ref" href="semi_af1.html#D6" target="_self" title="SEMI_AF1:def.6">Def6</a></i>;<br/>
<a NAME="E2:88"/><b>then </b>
 <a href="semi_af1.html#K1" title="SEMI_AF1:func.1">sum</a> <span class="p1">(<span class="default"><a href="semi_af1.html#K2" title="SEMI_AF1:func.2">opposite</a> <font color="Maroon" title="c2">o</font>,<font color="Maroon" title="c2">o</font></span>)</span>,<font color="Maroon" title="c2">o</font>,<font color="Maroon" title="c2">o</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">o</font>
 
<b>by </b><i><a class="ref" href="semi_af1.html#T102" target="_self" title="SEMI_AF1:th.102">Th102</a></i>;<br/>
<b>hence </b><a NAME="E3:88"/>
 <a href="semi_af1.html#K2" title="SEMI_AF1:func.2">opposite</a> <font color="Maroon" title="c2">o</font>,<font color="Maroon" title="c2">o</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">o</font>
 <b>by </b><i><a class="ref" href="semi_af1.html#T99" target="_self" title="SEMI_AF1:th.99">Th99</a></i>;<br/>


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