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<b>let </b><font color="Maroon" title="c1">Y</font> be   <a href="subset_1.html#NM2" title="SUBSET_1:NM.2">Subset</a> of <a href="numbers.html#K2" title="NUMBERS:func.2">COMPLEX</a> ;<br/><b>let </b><font color="Maroon" title="c2">f</font> be   <a href="partfun1.html#NM1" title="PARTFUN1:NM.1">PartFunc</a> of  <a href="numbers.html#K2" title="NUMBERS:func.2">COMPLEX</a> , <a href="numbers.html#K2" title="NUMBERS:func.2">COMPLEX</a> ;<br/>



<b>assume </b><b>that </b><br/><a NAME="E1:77"/><i><font color="Green" title="E49">A1</font></i>: 
<font color="Maroon" title="c1">Y</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a>  <a href="relset_1.html#K4" title="RELSET_1:func.4">dom</a> <font color="Maroon" title="c2">f</font>
 <b>and </b><br/><a NAME="E2:77"/><i><font color="Green" title="E50">A2</font></i>: 
<font color="Maroon" title="c1">Y</font> is <a href="cfcont_1.html#V1" title="CFCONT_1:attr.1">compact</a>
 <b>and </b><br/><a NAME="E3:77"/><i><font color="Green" title="E51">A3</font></i>: 
<font color="Maroon" title="c2">f</font> <a href="cfcont_1.html#R2" title="CFCONT_1:pred.2">is_continuous_on</a> <font color="Maroon" title="c1">Y</font>
 ;<br/>

<i><font color="Green" title="E52">A4</font></i>:  <a href="relset_1.html#K4" title="RELSET_1:func.4">dom</a> <span class="p1">(<span class="default"><font color="Maroon" title="c2">f</font> <a href="relset_1.html#K8" title="RELSET_1:func.8">|</a> <font color="Maroon" title="c1">Y</font></span>)</span> = 
<span class="p1">(<span class="default"><a href="relset_1.html#K4" title="RELSET_1:func.4">dom</a> <font color="Maroon" title="c2">f</font></span>)</span> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c1">Y</font>
<b>by </b><i><a class="ref" href="relat_1.html#T90" title="RELAT_1:th.90">RELAT_1:90</a></i>
<br/>.= 
<font color="Maroon" title="c1">Y</font>
<b>by </b><i><a class="txt" href="cfcont_1.html#E1:77"><i><font color="Green" title="E49">A1</font></i></a>, <a class="ref" href="xboole_1.html#T28" title="XBOOLE_1:th.28">XBOOLE_1:28</a></i>
;<br/>
<a NAME="E5:77"/>
<font color="Maroon" title="c2">f</font> <a href="relset_1.html#K8" title="RELSET_1:func.8">|</a> <font color="Maroon" title="c1">Y</font> <a href="cfcont_1.html#R2" title="CFCONT_1:pred.2">is_continuous_on</a> <font color="Maroon" title="c1">Y</font>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="77_2"><b>proof </b></a><div class="add">

<b>thus </b><a NAME="E1:77_2"/>
<font color="Maroon" title="c1">Y</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a>  <a href="relset_1.html#K4" title="RELSET_1:func.4">dom</a> <span class="p1">(<span class="default"><font color="Maroon" title="c2">f</font> <a href="relset_1.html#K8" title="RELSET_1:func.8">|</a> <font color="Maroon" title="c1">Y</font></span>)</span>
 <b>by </b><i><a class="txt" href="cfcont_1.html#E4:77"><i><font color="Green" title="E52">A4</font></i></a></i>; <i><font color="Red">:: according to </font></i><a class="ref" href="cfcont_1.html#D5" target="_self" title="CFCONT_1:def.5">CFCONT_1:def 5</a><br/>

<b>let </b><font color="Maroon" title="c3">g</font> be    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of  <a href="numbers.html#K2" title="NUMBERS:func.2">COMPLEX</a> ;<br/>

<b>assume </b><a NAME="E2:77_2"/>
<font color="Maroon" title="c3">g</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a> <font color="Maroon" title="c1">Y</font>
 ;<br/>

<a NAME="E3:77_2"/><b>then </b>
<font color="Maroon" title="c2">f</font> <a href="relset_1.html#K8" title="RELSET_1:func.8">|</a> <font color="Maroon" title="c1">Y</font> <a href="cfcont_1.html#R1" title="CFCONT_1:pred.1">is_continuous_in</a> <font color="Maroon" title="c3">g</font>
 
<b>by </b><i><a class="txt" href="cfcont_1.html#E3:77"><i><font color="Green" title="E51">A3</font></i></a>, <a class="ref" href="cfcont_1.html#D5" target="_self" title="CFCONT_1:def.5">Def5</a></i>;<br/>
<b>hence </b><a NAME="E4:77_2"/>
<span class="p1">(<span class="default"><font color="Maroon" title="c2">f</font> <a href="relset_1.html#K8" title="RELSET_1:func.8">|</a> <font color="Maroon" title="c1">Y</font></span>)</span> <a href="relset_1.html#K8" title="RELSET_1:func.8">|</a> <font color="Maroon" title="c1">Y</font> <a href="cfcont_1.html#R1" title="CFCONT_1:pred.1">is_continuous_in</a> <font color="Maroon" title="c3">g</font>
 <b>by </b><i><a class="ref" href="relat_1.html#T101" title="RELAT_1:th.101">RELAT_1:101</a></i>;<br/>


</div><b>end;</b></div>
<a NAME="E6:77"/><b>then </b>
 <a href="relset_1.html#K5" title="RELSET_1:func.5">rng</a> <span class="p1">(<span class="default"><font color="Maroon" title="c2">f</font> <a href="relset_1.html#K8" title="RELSET_1:func.8">|</a> <font color="Maroon" title="c1">Y</font></span>)</span> is <a href="cfcont_1.html#V1" title="CFCONT_1:attr.1">compact</a>
 
<b>by </b><i><a class="txt" href="cfcont_1.html#E2:77"><i><font color="Green" title="E50">A2</font></i></a>, <a class="txt" href="cfcont_1.html#E4:77"><i><font color="Green" title="E52">A4</font></i></a>, <a class="ref" href="cfcont_1.html#T73" target="_self" title="CFCONT_1:th.73">Th73</a></i>;<br/>
<b>hence </b><a NAME="E7:77"/>
<font color="Maroon" title="c2">f</font> <a href="relset_1.html#K10" title="RELSET_1:func.10">.:</a> <font color="Maroon" title="c1">Y</font> is <a href="cfcont_1.html#V1" title="CFCONT_1:attr.1">compact</a>
 <b>by </b><i><a class="ref" href="relat_1.html#T148" title="RELAT_1:th.148">RELAT_1:148</a></i>;<br/>


</div>
