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<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="4_1_1_1"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:4_1_1_1"/><i><font color="Green">E1</font></i>: 
 <a href="pre_topc.html#K4">Cl</a> <font color="Maroon">c<sub>2</sub></font> is <a href="realset1.html#V1">trivial</a>
 ;<br/><a NAME="E2:4_1_1_1"/>
<font color="Maroon">c<sub>2</sub></font> <a href="tarski.html#R1">c=</a>  <a href="pre_topc.html#K4">Cl</a> <font color="Maroon">c<sub>2</sub></font>
 <b>by </b><i><a class="ref" href="pre_topc.html#T48">PRE_TOPC:48</a></i>;<br/><b>hence </b><a NAME="E3:4_1_1_1"/>
contradiction
 <b>by </b><i><a class="txt" href="tex_4.html#E1:4_1_1_1"><i><font color="Green">E1</font></i></a>, <a class="ref" href="tex_2.html#T1">TEX_2:1</a></i>;<br/></div><b>end;</b></div>
<b>hence </b><a NAME="E2:4_1_1"/>
not  <a href="pre_topc.html#K4">Cl</a> <font color="Maroon">c<sub>2</sub></font> is <a href="realset1.html#V1">trivial</a>
 ;<br/>


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