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<b>let </b><font color="Maroon" title="c1">S</font> be   <a href="incsp_1.html#NM4" title="INCSP_1:NM.4">IncSpace</a>;<br/><b>let </b><font color="Maroon" title="c2">L</font> be   <a href="incsp_1.html#NM2" title="INCSP_1:NM.2">LINE</a> of <font color="Maroon" title="c1">S</font>;<br/><b>let </b><font color="Maroon" title="c3">P</font> be   <a href="incsp_1.html#NM3" title="INCSP_1:NM.3">PLANE</a> of <font color="Maroon" title="c1">S</font>;<br/><b>let </b><font color="Maroon" title="c4">F</font> be   <a href="subset_1.html#NM2" title="SUBSET_1:NM.2">Subset</a> of the <a href="incsp_1.html#U1" title="INCSP_1:sel.1">Points</a> of <font color="Maroon" title="c1">S</font>;<br/>







<b>assume </b><b>that </b><br/><a NAME="E1:30"/><i><font color="Green" title="E21">A1</font></i>: 
<font color="Maroon" title="c4">F</font> <a href="incsp_1.html#R4" title="INCSP_1:pred.4">on</a> <font color="Maroon" title="c2">L</font>
 <b>and </b><br/><a NAME="E2:30"/><i><font color="Green" title="E22">A2</font></i>: 
<font color="Maroon" title="c2">L</font> <a href="incsp_1.html#R3" title="INCSP_1:pred.3">on</a> <font color="Maroon" title="c3">P</font>
 ;<br/>

<b>let </b><font color="Maroon" title="c5">A</font> be   <a href="incsp_1.html#NM1" title="INCSP_1:NM.1">POINT</a> of <font color="Maroon" title="c1">S</font>; <i><font color="Red">:: according to </font></i><a class="ref" href="incsp_1.html#D5" target="_self" title="INCSP_1:def.5">INCSP_1:def 5</a><br/>

<b>assume </b><a NAME="E3:30"/>
<font color="Maroon" title="c5">A</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a> <font color="Maroon" title="c4">F</font>
 ;<br/>

<a NAME="E4:30"/><b>then </b>
<font color="Maroon" title="c5">A</font> <a href="incsp_1.html#R1" title="INCSP_1:pred.1">on</a> <font color="Maroon" title="c2">L</font>
 
<b>by </b><i><a class="txt" href="incsp_1.html#E1:30"><i><font color="Green" title="E21">A1</font></i></a>, <a class="ref" href="incsp_1.html#D4" target="_self" title="INCSP_1:def.4">Def4</a></i>;<br/>
<b>hence </b><a NAME="E5:30"/>
<font color="Maroon" title="c5">A</font> <a href="incsp_1.html#R2" title="INCSP_1:pred.2">on</a> <font color="Maroon" title="c3">P</font>
 <b>by </b><i><a class="txt" href="incsp_1.html#E2:30"><i><font color="Green" title="E22">A2</font></i></a>, <a class="ref" href="incsp_1.html#D8" target="_self" title="INCSP_1:def.8">Def8</a></i>;<br/>


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