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<b>let </b><font color="Maroon">D</font> be  non <a href="xboole_0.html#V1">empty</a>  <a href="hidden.html#M1">set</a> ;<br/><b>let </b><font color="Maroon">F</font> be   <a href="partfun1.html#NM1">PartFunc</a> of <font color="Maroon">D</font>, <a href="numbers.html#K1">REAL</a> ;<br/>



<a NAME="E1:70"/><i><font color="Green">E30</font></i>: 
 <a href="relset_1.html#K4">dom</a> <span class="p1">(<span class="default"><font color="Maroon">F</font> <a href="rfunct_3.html#K21" target="_self">-</a> 0</span>)</span> <a href="hidden.html#R1">=</a>  <a href="relset_1.html#K4">dom</a> <font color="Maroon">F</font>
 
<b>by </b><i><a class="txt" href="rfunct_3.html#E10"><i><font color="Green">Lemma45</font></i></a></i>;<br/>
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="70_1"><b>now </b></a><div class="add"><b>let </b><font color="Maroon">d</font> be    <a href="subset_1.html#M1">Element</a> of <font color="Maroon">D</font>;<br/><b>assume </b><a NAME="E1:70_1"/>
<font color="Maroon">d</font> <a href="hidden.html#R2">in</a>  <a href="relset_1.html#K4">dom</a> <font color="Maroon">F</font>
 ;<br/><b>hence </b><span class="p1">(<span class="default"><font color="Maroon">F</font> <a href="rfunct_3.html#K21" target="_self">-</a> 0</span>)</span> <a href="seq_1.html#K2">.</a> <font color="Maroon">d</font> = 
<span class="p1">(<span class="default"><font color="Maroon">F</font> <a href="seq_1.html#K2">.</a> <font color="Maroon">d</font></span>)</span> <a href="real_1.html#K5">-</a> 0
<b>by </b><i>, <a class="txt" href="rfunct_3.html#E10"><i><font color="Green">Lemma45</font></i></a></i>
<br/>.= 
<font color="Maroon">F</font> <a href="seq_1.html#K2">.</a> <font color="Maroon">d</font>

;<br/><br/></div><b>end;</b></div>
<b>hence </b><a NAME="E3:70"/>
<font color="Maroon">F</font> <a href="rfunct_3.html#K21" target="_self">-</a> 0 <a href="hidden.html#R1">=</a> <font color="Maroon">F</font>
 <b>by </b><i>, <a class="ref" href="partfun1.html#T34">PARTFUN1:34</a></i>;<br/>


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