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<div class="add">

<b>let </b><font color="Maroon">c<sub>1</sub></font> be   <a href="nat_1.html#NM1">Nat</a>;<br/>

<b>assume </b><a NAME="E1:38"/>
<font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0
 ;<br/>

<a NAME="E2:38"/><b>then </b>
<font color="Maroon">c<sub>1</sub></font> <a href="xxreal_0.html#NR4" target="_self">&gt;</a> 0
 
;<br/>
<a NAME="E3:38"/><b>then </b>
( ( <font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#R1">=</a> 0 implies 1 <a href="hidden.html#R1">=</a> 0 ) &amp; ( 1 <a href="hidden.html#R1">=</a> 0 implies <font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#R1">=</a> 0 ) &amp; <font color="Maroon">c<sub>1</sub></font> <a href="xxreal_0.html#NR2" target="_self">&gt;=</a> 1 <a href="binop_2.html#K23">+</a> 0 )
 
<b>by </b><i><a class="ref" href="nat_1.html#T38">NAT_1:38</a></i>;<br/>
<b>then consider </b><font color="Maroon">c<sub>2</sub></font> being   <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">c<sub>1</sub></font>,1<b> such that </b><br/><a NAME="E5:38"/><i><font color="Green">E24</font></i>: 
( <font color="Maroon">c<sub>2</sub></font> is <a href="funct_2.html#V2">onto</a> &amp; <font color="Maroon">c<sub>2</sub></font> is <a href="stirl2_1.html#V1" target="_self">"increasing</a> )
 <b>by </b><i><a class="ref" href="stirl2_1.html#T23" target="_self">Th23</a></i>;<br/>
<b>set </b><font color="Maroon">c<sub>3</sub></font> = <span class="p1">{<span class="default"> <font color="Olive">b<sub>1</sub></font> where B is   <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">c<sub>1</sub></font>,1 : ( <font color="Olive">b<sub>1</sub></font> is <a href="funct_2.html#V2">onto</a> &amp; <font color="Olive">b<sub>1</sub></font> is <a href="stirl2_1.html#V1" target="_self">"increasing</a> ) </span>}</span> ;<br/>
<a NAME="E6:38"/><i><font color="Green">E25</font></i>: 
<span class="p1">{<span class="default"> <font color="Olive">b<sub>1</sub></font> where B is   <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">c<sub>1</sub></font>,1 : ( <font color="Olive">b<sub>1</sub></font> is <a href="funct_2.html#V2">onto</a> &amp; <font color="Olive">b<sub>1</sub></font> is <a href="stirl2_1.html#V1" target="_self">"increasing</a> ) </span>}</span>  <a href="tarski.html#R1">c=</a> <span class="p1"><a href="domain_1.html#K6">{</a><span class="default"><font color="Maroon">c<sub>2</sub></font></span><a href="domain_1.html#K6">}</a></span>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="38_1"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">c<sub>4</sub></font> be    <a href="hidden.html#M1">set</a> ; <i><font color="Red">:: according to </font></i><a class="ref" href="tarski.html#D3">TARSKI:def 3</a><br/>

<b>assume </b><a NAME="E1:38_1"/><i><font color="Green">E26</font></i>: 
<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R2">in</a> <span class="p1">{<span class="default"> <font color="Olive">b<sub>1</sub></font> where B is   <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">c<sub>1</sub></font>,1 : ( <font color="Olive">b<sub>1</sub></font> is <a href="funct_2.html#V2">onto</a> &amp; <font color="Olive">b<sub>1</sub></font> is <a href="stirl2_1.html#V1" target="_self">"increasing</a> ) </span>}</span> 
 ;<br/>

<b>consider </b><font color="Maroon">c<sub>5</sub></font> being   <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">c<sub>1</sub></font>,1<b> such that </b><br/><a NAME="E3:38_1"/><i><font color="Green">E27</font></i>: 
( <font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>5</sub></font> &amp; <font color="Maroon">c<sub>5</sub></font> is <a href="funct_2.html#V2">onto</a> &amp; <font color="Maroon">c<sub>5</sub></font> is <a href="stirl2_1.html#V1" target="_self">"increasing</a> )
 <b>by </b><i><a class="txt" href="stirl2_1.html#E1:38_1"><i><font color="Green">E26</font></i></a></i>;<br/>
<a NAME="E4:38_1"/>
<font color="Maroon">c<sub>2</sub></font> <a href="funct_2.html#R2">=</a> <font color="Maroon">c<sub>5</sub></font>
 
<b>by </b><i><a class="ref" href="card_5.html#T1">CARD_5:1</a>, <a class="ref" href="funct_2.html#T66">FUNCT_2:66</a></i>;<br/>
<b>hence </b><a NAME="E5:38_1"/>
<font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R2">in</a> <span class="p1"><a href="domain_1.html#K6">{</a><span class="default"><font color="Maroon">c<sub>2</sub></font></span><a href="domain_1.html#K6">}</a></span>
 <b>by </b><i><a class="txt" href="stirl2_1.html#E3:38_1"><i><font color="Green">E27</font></i></a>, <a class="ref" href="tarski.html#D1">TARSKI:def 1</a></i>;<br/>


</div><b>end;</b></div>
<a NAME="E7:38"/>
<font color="Maroon">c<sub>2</sub></font> <a href="hidden.html#R2">in</a> <span class="p1">{<span class="default"> <font color="Olive">b<sub>1</sub></font> where B is   <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">c<sub>1</sub></font>,1 : ( <font color="Olive">b<sub>1</sub></font> is <a href="funct_2.html#V2">onto</a> &amp; <font color="Olive">b<sub>1</sub></font> is <a href="stirl2_1.html#V1" target="_self">"increasing</a> ) </span>}</span> 
 
<b>by </b><i><a class="txt" href="stirl2_1.html#E5:38"><i><font color="Green">E24</font></i></a></i>;<br/>
<a NAME="E8:38"/><b>then </b>
<span class="p1">{<span class="default"> <font color="Olive">b<sub>1</sub></font> where B is   <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">c<sub>1</sub></font>,1 : ( <font color="Olive">b<sub>1</sub></font> is <a href="funct_2.html#V2">onto</a> &amp; <font color="Olive">b<sub>1</sub></font> is <a href="stirl2_1.html#V1" target="_self">"increasing</a> ) </span>}</span>  <a href="hidden.html#R1">=</a> <span class="p1"><a href="domain_1.html#K6">{</a><span class="default"><font color="Maroon">c<sub>2</sub></font></span><a href="domain_1.html#K6">}</a></span>
 
<b>by </b><i><a class="txt" href="stirl2_1.html#E6:38"><i><font color="Green">E25</font></i></a>, <a class="ref" href="zfmisc_1.html#T39">ZFMISC_1:39</a></i>;<br/>
<a NAME="E9:38"/><b>then </b>
 <a href="card_1.html#K1">Card</a> <span class="p1">{<span class="default"> <font color="Olive">b<sub>1</sub></font> where B is   <a href="funct_2.html#NM1">Function</a> of <font color="Maroon">c<sub>1</sub></font>,1 : ( <font color="Olive">b<sub>1</sub></font> is <a href="funct_2.html#V2">onto</a> &amp; <font color="Olive">b<sub>1</sub></font> is <a href="stirl2_1.html#V1" target="_self">"increasing</a> ) </span>}</span>  <a href="hidden.html#R1">=</a> 1
 
<b>by </b><i><a class="ref" href="card_1.html#T50">CARD_1:50</a></i>;<br/>
<b>hence </b><a NAME="E10:38"/>
<font color="Maroon">c<sub>1</sub></font> <a href="stirl2_1.html#K3" target="_self">block</a> 1 <a href="hidden.html#R1">=</a> 1
 ;<br/>


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