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<b>let </b><font color="Maroon">c<sub>1</sub></font> be   <a href="nat_1.html#NM1">Nat</a>;<br/><b>let </b><font color="Maroon">c<sub>2</sub></font> be   <a href="pre_topc.html#NM2">Point</a> of <span class="p1">(<span class="default"><a href="euclid.html#K15" target="_self">TOP-REAL</a> <font color="Maroon">c<sub>1</sub></font></span>)</span>;<br/>



<b>reconsider </b><font color="Maroon">c<sub>3</sub></font> = <font color="Maroon">c<sub>2</sub></font>, <font color="Maroon">c<sub>4</sub></font> =  <a href="euclid.html#K19" target="_self">-</a> <font color="Maroon">c<sub>2</sub></font> as    <a href="finseq_2.html#M2">Element</a> of  <a href="euclid.html#K1" target="_self">REAL</a> <font color="Maroon">c<sub>1</sub></font> ;<br/>
<b>reconsider </b><font color="Maroon">c<sub>5</sub></font> = <font color="Maroon">c<sub>3</sub></font> as    <a href="finseq_2.html#M2">Element</a> of <font color="Maroon">c<sub>1</sub></font> <a href="finseq_2.html#K4">-tuples_on</a> <a href="numbers.html#K1">REAL</a>  ;<br/>
<b>thus </b> <a href="euclid.html#K19" target="_self">-</a> <span class="p1">(<span class="default"><a href="euclid.html#K19" target="_self">-</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> = 
 <a href="euclid.html#K6" target="_self">-</a> <font color="Maroon">c<sub>4</sub></font>
<b>by </b><i><a class="ref" href="euclid.html#D12" target="_self">Def12</a></i>
<br/>.= 
 <a href="rvsum_1.html#K6">-</a> <span class="p1">(<span class="default"><a href="rvsum_1.html#K6">-</a> <font color="Maroon">c<sub>5</sub></font></span>)</span>
<b>by </b><i><a class="ref" href="euclid.html#D12" target="_self">Def12</a></i>
<br/>.= 
<font color="Maroon">c<sub>2</sub></font>

;<br/>


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