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<span class="kw">assume </span><a NAME="E1:21_1_1"/>
not  <a href="member_1.html#K5" title="MEMBER_1:func.5">--</a> <font color="Maroon" title="c1">A</font> is  <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a> 
 ; <a class="txt" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="Red">::  thesis: </font></span></a><span class="hide"> contradiction</span><br/>

<a NAME="E2:21_1_1"/><span class="kw">then </span>
the    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of  <a href="member_1.html#K5" title="MEMBER_1:func.5">--</a> <font color="Maroon" title="c1">A</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="member_1.html#K5" title="MEMBER_1:func.5">--</a> <font color="Maroon" title="c1">A</font>
 
;<br/>
<a NAME="E3:21_1_1"/><span class="kw">then </span>
 ex <font color="Olive" title="b1">c</font> being   <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of  <a href="numbers.html#K2" title="NUMBERS:func.2">COMPLEX</a>  st <br/>( the    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of  <a href="member_1.html#K5" title="MEMBER_1:func.5">--</a> <font color="Maroon" title="c1">A</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="binop_2.html#K1" title="BINOP_2:func.1">-</a> <font color="Olive" title="b1">c</font> &amp; <font color="Olive" title="b1">c</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a> <font color="Maroon" title="c1">A</font> )
 
;<br/>
<span class="kw">hence </span><a NAME="E4:21_1_1"/>
contradiction
 ; <a class="txt" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="Red">::  thesis: </font></span></a><span class="hide"> verum</span><br/>


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