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<b>let </b><font color="Maroon" title="c1">y1</font>, <font color="Maroon" title="c2">y2</font> be   <a href="real_1.html#NM1" title="REAL_1:NM.1">Real</a>;<br/>



<span class="p1"><a href="euclid_5.html#K4" title="EUCLID_5:func.4">|[</a><span class="default">0,<font color="Maroon" title="c1">y1</font>,0</span><a href="euclid_5.html#K4" title="EUCLID_5:func.4">]|</a></span> <a href="euclid_5.html#K5" title="EUCLID_5:func.5">&lt;X&gt;</a> <span class="p1"><a href="euclid_5.html#K4" title="EUCLID_5:func.4">|[</a><span class="default">0,<font color="Maroon" title="c2">y2</font>,0</span><a href="euclid_5.html#K4" title="EUCLID_5:func.4">]|</a></span> = 
<span class="p1"><a href="euclid_5.html#K4" title="EUCLID_5:func.4">|[</a><span class="default"><span class="p2">(<span class="default"><span class="p3">(<span class="default"><font color="Maroon" title="c1">y1</font> <a href="binop_2.html#K11" title="BINOP_2:func.11">*</a> 0</span>)</span> <a href="binop_2.html#K10" title="BINOP_2:func.10">-</a> <span class="p3">(<span class="default">0 <a href="binop_2.html#K11" title="BINOP_2:func.11">*</a> <font color="Maroon" title="c2">y2</font></span>)</span></span>)</span>,<span class="p2">(<span class="default"><span class="p3">(<span class="default">0 <a href="binop_2.html#K24" title="BINOP_2:func.24">*</a> 0</span>)</span> <a href="binop_2.html#K10" title="BINOP_2:func.10">-</a> <span class="p3">(<span class="default">0 <a href="binop_2.html#K24" title="BINOP_2:func.24">*</a> 0</span>)</span></span>)</span>,<span class="p2">(<span class="default"><span class="p3">(<span class="default">0 <a href="binop_2.html#K11" title="BINOP_2:func.11">*</a> <font color="Maroon" title="c2">y2</font></span>)</span> <a href="binop_2.html#K10" title="BINOP_2:func.10">-</a> <span class="p3">(<span class="default"><font color="Maroon" title="c1">y1</font> <a href="binop_2.html#K11" title="BINOP_2:func.11">*</a> 0</span>)</span></span>)</span></span><a href="euclid_5.html#K4" title="EUCLID_5:func.4">]|</a></span>
<b>by </b><i><a class="ref" href="euclid_5.html#T15" target="_self" title="EUCLID_5:th.15">Th15</a></i>
<br/>.= 
<span class="p1"><a href="euclid_5.html#K4" title="EUCLID_5:func.4">|[</a><span class="default"><span class="p2">(<span class="default">0 <a href="binop_2.html#K11" title="BINOP_2:func.11">*</a> <span class="p3">(<span class="default"><font color="Maroon" title="c1">y1</font> <a href="binop_2.html#K10" title="BINOP_2:func.10">-</a> <font color="Maroon" title="c2">y2</font></span>)</span></span>)</span>,<span class="p2">(<span class="default">0 <a href="binop_2.html#K11" title="BINOP_2:func.11">*</a> <span class="p3">(<span class="default">0 <a href="binop_2.html#K10" title="BINOP_2:func.10">-</a> 0</span>)</span></span>)</span>,<span class="p2">(<span class="default">0 <a href="binop_2.html#K11" title="BINOP_2:func.11">*</a> <span class="p3">(<span class="default"><font color="Maroon" title="c2">y2</font> <a href="binop_2.html#K10" title="BINOP_2:func.10">-</a> <font color="Maroon" title="c1">y1</font></span>)</span></span>)</span></span><a href="euclid_5.html#K4" title="EUCLID_5:func.4">]|</a></span>

<br/>.= 
0 <a href="euclid.html#K18" title="EUCLID:func.18">*</a> <span class="p1"><a href="euclid_5.html#K4" title="EUCLID_5:func.4">|[</a><span class="default"><span class="p2">(<span class="default"><font color="Maroon" title="c1">y1</font> <a href="binop_2.html#K10" title="BINOP_2:func.10">-</a> <font color="Maroon" title="c2">y2</font></span>)</span>,<span class="p2">(<span class="default">0 <a href="binop_2.html#K10" title="BINOP_2:func.10">-</a> 0</span>)</span>,<span class="p2">(<span class="default"><font color="Maroon" title="c2">y2</font> <a href="binop_2.html#K10" title="BINOP_2:func.10">-</a> <font color="Maroon" title="c1">y1</font></span>)</span></span><a href="euclid_5.html#K4" title="EUCLID_5:func.4">]|</a></span>
<b>by </b><i><a class="ref" href="euclid_5.html#T8" target="_self" title="EUCLID_5:th.8">Th8</a></i>
<br/>.= 
 <a href="euclid.html#K16" title="EUCLID:func.16">0.REAL</a> 3
<b>by </b><i><a class="ref" href="euclid.html#T33" title="EUCLID:th.33">EUCLID:33</a></i>
;<br/>
<b>hence </b><a NAME="E2:23"/>
<span class="p1"><a href="euclid_5.html#K4" title="EUCLID_5:func.4">|[</a><span class="default">0,<font color="Maroon" title="c1">y1</font>,0</span><a href="euclid_5.html#K4" title="EUCLID_5:func.4">]|</a></span> <a href="euclid_5.html#K5" title="EUCLID_5:func.5">&lt;X&gt;</a> <span class="p1"><a href="euclid_5.html#K4" title="EUCLID_5:func.4">|[</a><span class="default">0,<font color="Maroon" title="c2">y2</font>,0</span><a href="euclid_5.html#K4" title="EUCLID_5:func.4">]|</a></span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="euclid.html#K16" title="EUCLID:func.16">0.REAL</a> 3
 ;<br/>


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