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<b>let </b><font color="Maroon">a</font> be  <a href="xxreal_0.html#V1" target="_self">ext-real</a>  <a href="ordinal1.html#NM1" target="_self">number</a> ;<br/><b>let </b><font color="Maroon">c</font> be  <a href="xxreal_0.html#V1" target="_self">ext-real</a>  <a href="ordinal1.html#NM1" target="_self">number</a> ;<br/><b>let </b><font color="Maroon">b</font> be  <a href="xxreal_0.html#V1" target="_self">ext-real</a>  <a href="ordinal1.html#NM1" target="_self">number</a> ;<br/>





<b>assume </b><a NAME="E1:49"/><i><font color="Green">E19</font></i>: 
<font color="Maroon">a</font> <a href="xxreal_0.html#R1" target="_self">&lt;=</a> <font color="Maroon">c</font>
 ;<br/>

<div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_1"><b>per </b></a><a class="txt" onclick="hs(this)" href="javascript:()"><b>cases </b></a><span class="hide"><a NAME="E1:49_1"/>
( <font color="Maroon">a</font> <a href="xxreal_0.html#R1" target="_self">&lt;=</a> <font color="Maroon">b</font> or <font color="Maroon">b</font> <a href="xxreal_0.html#R1" target="_self">&lt;=</a> <font color="Maroon">a</font> )
 </span>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_1_1"><b>suppose </b></a><a NAME="E1:49_1_1"/><i><font color="Green">E20</font></i>: 
<font color="Maroon">a</font> <a href="xxreal_0.html#R1" target="_self">&lt;=</a> <font color="Maroon">b</font>
 ;<br/><div class="add"><a NAME="E2:49_1_1"/><b>then </b>
<font color="Maroon">a</font> <a href="xxreal_0.html#R1" target="_self">&lt;=</a>  <a href="xxreal_0.html#K3" target="_self">min</a> <font color="Maroon">b</font>,<font color="Maroon">c</font>
 <b>by </b><i>, </i>;<br/><b>hence </b> <a href="xxreal_0.html#K4" target="_self">max</a> <font color="Maroon">a</font>,<span class="p1">(<span class="default"><a href="xxreal_0.html#K3" target="_self">min</a> <font color="Maroon">b</font>,<font color="Maroon">c</font></span>)</span> = 
 <a href="xxreal_0.html#K3" target="_self">min</a> <font color="Maroon">b</font>,<font color="Maroon">c</font>
<b>by </b><i><a class="txt" href="xxreal_0.html#E1:49_1_1"><i><font color="Green">E20</font></i></a></i>
<br/>.= 
 <a href="xxreal_0.html#K3" target="_self">min</a> <span class="p1">(<span class="default"><a href="xxreal_0.html#K4" target="_self">max</a> <font color="Maroon">a</font>,<font color="Maroon">b</font></span>)</span>,<font color="Maroon">c</font>
<b>by </b><i>, <a class="txt" href="xxreal_0.html#E1:49_1_1"><i><font color="Green">E20</font></i></a></i>
;<br/><br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_1_2"><b>suppose </b></a><a NAME="E1:49_1_2"/><i><font color="Green">E21</font></i>: 
<font color="Maroon">b</font> <a href="xxreal_0.html#R1" target="_self">&lt;=</a> <font color="Maroon">a</font>
 ;<br/><div class="add"><a NAME="E2:49_1_2"/><b>then </b>
<font color="Maroon">b</font> <a href="xxreal_0.html#R1" target="_self">&lt;=</a> <font color="Maroon">c</font>
 <b>by </b><i>, </i>;<br/><b>hence </b> <a href="xxreal_0.html#K4" target="_self">max</a> <font color="Maroon">a</font>,<span class="p1">(<span class="default"><a href="xxreal_0.html#K3" target="_self">min</a> <font color="Maroon">b</font>,<font color="Maroon">c</font></span>)</span> = 
 <a href="xxreal_0.html#K4" target="_self">max</a> <font color="Maroon">a</font>,<font color="Maroon">b</font>
<b>by </b><i><a class="txt" href="xxreal_0.html#E1:49"><i><font color="Green">E19</font></i></a></i>
<br/>.= 
<font color="Maroon">a</font>
<b>by </b><i>, </i>
<br/>.= 
 <a href="xxreal_0.html#K3" target="_self">min</a> <font color="Maroon">a</font>,<font color="Maroon">c</font>
<b>by </b><i>, <a class="txt" href="xxreal_0.html#E1:49"><i><font color="Green">E19</font></i></a></i>
<br/>.= 
 <a href="xxreal_0.html#K3" target="_self">min</a> <span class="p1">(<span class="default"><a href="xxreal_0.html#K4" target="_self">max</a> <font color="Maroon">a</font>,<font color="Maroon">b</font></span>)</span>,<font color="Maroon">c</font>
<b>by </b><i>, </i>
;<br/><br/></div><b>end;</b></div></div><b>end;</b></div>

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