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<b>let </b><font color="Maroon">c<sub>2</sub></font> be  <a href="ordinal1.html#V7">natural</a>  <a href="ordinal1.html#NM1" target="_self">number</a> ;<br/>

<b>set </b><font color="Maroon">c<sub>3</sub></font> =  <a href="int_3.html#K9" target="_self">INT.Ring</a> <font color="Maroon">c<sub>2</sub></font>;<br/>
<b>assume </b><a NAME="E1:63"/><i><font color="Green">E45</font></i>: 
1 <a href="xxreal_0.html#NR3" target="_self">&lt;</a> <font color="Maroon">c<sub>2</sub></font>
 ;<br/>

<a NAME="E2:63"/><b>then </b><i><font color="Green">E46</font></i>: 
 <a href="int_3.html#K9" target="_self">INT.Ring</a> <font color="Maroon">c<sub>2</sub></font> is <a href="group_1.html#V2">unital</a>
 
<b>by </b><i><a class="txt" href="int_3.html#E50"><i><font color="Green">Lemma43</font></i></a></i>;<br/>
<b>reconsider </b><font color="Maroon">c<sub>4</sub></font> = 1 as   <a href="struct_0.html#NM1">Element</a> of <span class="p1">(<span class="default"><a href="int_3.html#K9" target="_self">INT.Ring</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <b>by </b><i><a class="txt" href="int_3.html#E1:63"><i><font color="Green">E45</font></i></a>, <a class="ref" href="gr_cy_1.html#T10">GR_CY_1:10</a></i>;<br/>
<a NAME="E4:63"/>
for <font color="Olive">b<sub>1</sub></font> being  <a href="struct_0.html#NM1">Element</a> of <span class="p1">(<span class="default"><a href="int_3.html#K9" target="_self">INT.Ring</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> holds <br/>( <font color="Olive">b<sub>1</sub></font> <a href="group_1.html#K1">*</a> <font color="Maroon">c<sub>4</sub></font> <a href="hidden.html#R1">=</a> <font color="Olive">b<sub>1</sub></font> &amp; <font color="Maroon">c<sub>4</sub></font> <a href="group_1.html#K1">*</a> <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1">=</a> <font color="Olive">b<sub>1</sub></font> )
 
<b>by </b><i><a class="txt" href="int_3.html#E1:63"><i><font color="Green">E45</font></i></a>, <a class="txt" href="int_3.html#E49"><i><font color="Green">Lemma42</font></i></a></i>;<br/>
<b>hence </b><a NAME="E5:63"/>
 <a href="group_1.html#K2">1.</a> <span class="p1">(<span class="default"><a href="int_3.html#K9" target="_self">INT.Ring</a> <font color="Maroon">c<sub>2</sub></font></span>)</span> <a href="hidden.html#R1">=</a> 1
 <b>by </b><i><a class="txt" href="int_3.html#E2:63"><i><font color="Green">E46</font></i></a>, <a class="ref" href="group_1.html#D5">GROUP_1:def 5</a></i>;<br/>


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