<?xml version="1.0"?>
<div class="add">

<b>let </b><font color="Maroon">X</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">Y</font> be  non <a href="xboole_0.html#V1">empty</a> <a href="subset_1.html#NM2">Subset</a> of <a href="numbers.html#K6">ExtREAL</a> , <font color="Maroon">Z</font> be  non <a href="xboole_0.html#V1">empty</a> <a href="subset_1.html#NM2">Subset</a> of <a href="numbers.html#K6">ExtREAL</a> ;<br/>



<b>assume </b><a NAME="E1:66"/><i><font color="Green">E24</font></i>: 
( <font color="Maroon">Y</font> <a href="tarski.html#R1">c=</a>  <a href="supinf_1.html#K3">REAL</a>  &amp; <font color="Maroon">Z</font> <a href="tarski.html#R1">c=</a>  <a href="supinf_1.html#K3">REAL</a>  )
 ;<br/>

<b>let </b><font color="Maroon">F1</font> be   <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">X</font>,<font color="Maroon">Y</font>;<br/><b>let </b><font color="Maroon">F2</font> be   <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">X</font>,<font color="Maroon">Z</font>;<br/>



<b>assume </b><a NAME="E2:66"/><i><font color="Green">E28</font></i>: 
( <font color="Maroon">F1</font> is <a href="supinf_2.html#V2" target="_self">bounded_below</a> &amp; <font color="Maroon">F2</font> is <a href="supinf_2.html#V2" target="_self">bounded_below</a> )
 ;<br/>

<a NAME="E3:66"/><i><font color="Green">E29</font></i>: 
( not <!--HUMANRECFAILED-->(  <a href="supinf_1.html#K2">-infty</a>  <a href="hidden.html#R2">in</a> <font color="Maroon">Y</font> &amp;  <a href="supinf_1.html#K1">+infty</a>  <a href="hidden.html#R2">in</a> <font color="Maroon">Z</font> ) &amp; not <!--HUMANRECFAILED-->(  <a href="supinf_1.html#K1">+infty</a>  <a href="hidden.html#R2">in</a> <font color="Maroon">Y</font> &amp;  <a href="supinf_1.html#K2">-infty</a>  <a href="hidden.html#R2">in</a> <font color="Maroon">Z</font> ) )
 
<b>by </b><i><a class="txt" href="supinf_2.html#E7:66"><i><font color="Green">E52</font></i></a>, <a class="ref" href="supinf_1.html#T1">SUPINF_1:1</a></i>;<br/>
<a NAME="E4:66"/><i><font color="Green">E30</font></i>: 
( not  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font> <a href="hidden.html#R1">=</a>  <a href="supinf_1.html#K2">-infty</a>  &amp; not  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font> <a href="hidden.html#R1">=</a>  <a href="supinf_1.html#K2">-infty</a>  )
 
<b>by </b><i><a class="txt" href="supinf_2.html#E8:66"><i><font color="Green">E53</font></i></a>, <a class="ref" href="supinf_2.html#T13" target="_self">Th13</a></i>;<br/>
<a NAME="E5:66"/><i><font color="Green">E31</font></i>: 
(  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font> <a href="hidden.html#R2">in</a>  <a href="supinf_1.html#K3">REAL</a>  &amp;  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font> <a href="hidden.html#R2">in</a>  <a href="supinf_1.html#K3">REAL</a>  implies  <a href="supinf_1.html#K2">-infty</a>  <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font></span>)</span> <a href="supinf_2.html#K2" target="_self">+</a> <span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font></span>)</span> )
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="66_1"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:66_1"/><i><font color="Green">E50</font></i>: 
(  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font> <a href="hidden.html#R2">in</a>  <a href="supinf_1.html#K3">REAL</a>  &amp;  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font> <a href="hidden.html#R2">in</a>  <a href="supinf_1.html#K3">REAL</a>  )
 ;<br/>

<b>reconsider </b><font color="Maroon">a</font> =  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font>, <font color="Maroon">b</font> =  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font> as   <a href="supinf_1.html#NM3">R_eal</a> ;<br/>
<b>reconsider </b><font color="Maroon">a</font> = <font color="Maroon">a</font>, <font color="Maroon">b</font> = <font color="Maroon">b</font> as   <a href="real_1.html#NM1">Real</a> <b>by </b><i/>;<br/>
<a NAME="E4:66_1"/>
<span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font></span>)</span> <a href="supinf_2.html#K2" target="_self">+</a> <span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">a</font> <a href="real_1.html#K3">+</a> <font color="Maroon">b</font>
 
<b>by </b><i/>;<br/>
<b>hence </b><a NAME="E5:66_1"/>
 <a href="supinf_1.html#K2">-infty</a>  <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font></span>)</span> <a href="supinf_2.html#K2" target="_self">+</a> <span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font></span>)</span>
 <b>by </b><i><a class="ref" href="supinf_1.html#T31">SUPINF_1:31</a></i>;<br/>


</div><b>end;</b></div>
<a NAME="E6:66"/><i><font color="Green">E51</font></i>: 
(  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font> <a href="hidden.html#R2">in</a>  <a href="supinf_1.html#K3">REAL</a>  &amp;  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font> <a href="hidden.html#R1">=</a>  <a href="supinf_1.html#K1">+infty</a>  implies  <a href="supinf_1.html#K2">-infty</a>  <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font></span>)</span> <a href="supinf_2.html#K2" target="_self">+</a> <span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font></span>)</span> )
 
<b>by </b><i>, <a class="ref" href="supinf_1.html#T6">SUPINF_1:6</a>, <a class="ref" href="xxreal_0.html#T7">XXREAL_0:7</a></i>;<br/>
<a NAME="E7:66"/><i><font color="Green">E52</font></i>: 
(  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font> <a href="hidden.html#R1">=</a>  <a href="supinf_1.html#K1">+infty</a>  &amp;  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font> <a href="hidden.html#R2">in</a>  <a href="supinf_1.html#K3">REAL</a>  implies  <a href="supinf_1.html#K2">-infty</a>  <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font></span>)</span> <a href="supinf_2.html#K2" target="_self">+</a> <span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font></span>)</span> )
 
<b>by </b><i>, <a class="ref" href="supinf_1.html#T6">SUPINF_1:6</a>, <a class="ref" href="xxreal_0.html#T7">XXREAL_0:7</a></i>;<br/>
<a NAME="E8:66"/><i><font color="Green">E53</font></i>: 
(  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font> <a href="hidden.html#R1">=</a>  <a href="supinf_1.html#K1">+infty</a>  &amp;  <a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font> <a href="hidden.html#R1">=</a>  <a href="supinf_1.html#K1">+infty</a>  implies  <a href="supinf_1.html#K2">-infty</a>  <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F1</font></span>)</span> <a href="supinf_2.html#K2" target="_self">+</a> <span class="p1">(<span class="default"><a href="supinf_2.html#K9" target="_self">inf</a> <font color="Maroon">F2</font></span>)</span> )
 
<b>by </b><i>, <a class="ref" href="xxreal_0.html#T7">XXREAL_0:7</a></i>;<br/>
<a NAME="E9:66"/>
 <a href="supinf_1.html#K2">-infty</a>  <a href="xxreal_0.html#NR3" target="_self">&lt;</a>  <a href="supinf_2.html#K9" target="_self">inf</a> <span class="p1">(<span class="default"><font color="Maroon">F1</font> <a href="supinf_2.html#K11" target="_self">+</a> <font color="Maroon">F2</font></span>)</span>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="66_2"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:66_2"/>
 <a href="supinf_2.html#K9" target="_self">inf</a> <span class="p1">(<span class="default"><font color="Maroon">F1</font> <a href="supinf_2.html#K11" target="_self">+</a> <font color="Maroon">F2</font></span>)</span> <a href="xxreal_0.html#R1">&lt;=</a>  <a href="supinf_1.html#K2">-infty</a> 
 ;<br/>

<a NAME="E2:66_2"/><b>then </b>
(  not  <a href="supinf_1.html#K2">-infty</a>  <a href="xxreal_0.html#R1">&lt;=</a>  <a href="supinf_2.html#K9" target="_self">inf</a> <span class="p1">(<span class="default"><font color="Maroon">F1</font> <a href="supinf_2.html#K11" target="_self">+</a> <font color="Maroon">F2</font></span>)</span> or  <a href="supinf_2.html#K9" target="_self">inf</a> <span class="p1">(<span class="default"><font color="Maroon">F1</font> <a href="supinf_2.html#K11" target="_self">+</a> <font color="Maroon">F2</font></span>)</span> <a href="hidden.html#R1">=</a>  <a href="supinf_1.html#K2">-infty</a>  )
 
<b>by </b><i><a class="ref" href="supinf_1.html#T22">SUPINF_1:22</a></i>;<br/>
<b>hence </b><a NAME="E3:66_2"/>
contradiction
 <b>by </b><i>, , , , , , , <a class="ref" href="supinf_1.html#T23">SUPINF_1:23</a>, <a class="ref" href="supinf_1.html#D7">SUPINF_1:def 7</a></i>;<br/>


</div><b>end;</b></div>
<b>hence </b><a NAME="E10:66"/>
<font color="Maroon">F1</font> <a href="supinf_2.html#K11" target="_self">+</a> <font color="Maroon">F2</font> is <a href="supinf_2.html#V2" target="_self">bounded_below</a>
 <b>by </b><i><a class="ref" href="supinf_2.html#T13" target="_self">Th13</a></i>;<br/>


</div>
