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<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="29_1"><b>now </b></a><div class="add"><b>let </b><font color="Maroon" title="c1">n</font> be    <a href="subset_1.html#M2" title="SUBSET_1:mode.2">Element</a> of  <a href="numbers.html#K5" title="NUMBERS:func.5">NAT</a> ;<br/><b>assume </b><a NAME="E1:29_1"/><i><font color="Green" title="E30">A1</font></i>: 
( 1 <a href="xxreal_0.html#R1" title="XXREAL_0:pred.1">&lt;</a> <font color="Maroon" title="c1">n</font> &amp; <font color="Maroon" title="c1">n</font> <a href="binop_2.html#K24" title="BINOP_2:func.24">*</a> <font color="Maroon" title="c1">n</font> <a href="xxreal_0.html#R1" title="XXREAL_0:pred.1">&lt;=</a> 7 &amp; <font color="Maroon" title="c1">n</font> is <a href="int_2.html#V1" title="INT_2:attr.1">prime</a> )
 ;<br/><a NAME="E2:29_1"/>
7 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1">(<span class="default">2 <a href="binop_2.html#K24" title="BINOP_2:func.24">*</a> 3</span>)</span> <a href="binop_2.html#K23" title="BINOP_2:func.23">+</a> 1
 ;<br/><a NAME="E3:29_1"/><b>then </b><i><font color="Green" title="E31">A2</font></i>: 
not 2 <a href="nat_d.html#R1" title="NAT_D:pred.1">divides</a> 7
 <b>by </b><i><a class="ref" href="nat_4.html#T9" target="_self" title="NAT_4:th.9">Th9</a></i>;<br/><a NAME="E4:29_1"/>
7 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1">(<span class="default">3 <a href="binop_2.html#K24" title="BINOP_2:func.24">*</a> 2</span>)</span> <a href="binop_2.html#K23" title="BINOP_2:func.23">+</a> 1
 ;<br/><a NAME="E5:29_1"/><b>then </b>
not 3 <a href="nat_d.html#R1" title="NAT_D:pred.1">divides</a> 7
 <b>by </b><i><a class="ref" href="nat_4.html#T9" target="_self" title="NAT_4:th.9">Th9</a></i>;<br/><b>hence </b><a NAME="E6:29_1"/>
not <font color="Maroon" title="c1">n</font> <a href="nat_d.html#R1" title="NAT_D:pred.1">divides</a> 7
 <b>by </b><i><a class="txt" href="nat_4.html#E1:29_1"><i><font color="Green" title="E30">A1</font></i></a>, <a class="txt" href="nat_4.html#E3:29_1"><i><font color="Green" title="E31">A2</font></i></a>, <a class="txt" href="nat_4.html#E28"><i><font color="Green" title="E28">Lm3</font></i></a></i>;<br/></div><b>end;</b></div>
<b>hence </b><a NAME="E2:29"/>
7 is <a href="int_2.html#V1" title="INT_2:attr.1">prime</a>
 <b>by </b><i><a class="ref" href="nat_4.html#T14" target="_self" title="NAT_4:th.14">Th14</a></i>;<br/>


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