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<b>consider </b><font color="Maroon">s1</font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">S</font>, <font color="Maroon">s2</font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">S</font><b> such that </b><br/><a NAME="E2:2_1_1"/><i><font color="Green">E54</font></i>: 
<font color="Maroon">s1</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">s2</font>
 <b>by </b><i><a class="ref" href="yellow_8.html#D1">YELLOW_8:def 1</a></i>;<br/>
<b>consider </b><font color="Maroon">t1</font> being   <a href="struct_0.html#NM1">Element</a> of <font color="Maroon">T</font>;<br/>
<div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="2_1_1_1"><b>per </b></a><a class="txt" onclick="hs(this)" href="javascript:()"><b>cases </b></a><span class="hide"><a NAME="E1:2_1_1_1"/>
( <font color="Maroon">s1</font> <a href="hidden.html#R1">=</a> <font color="Maroon">t1</font> or <font color="Maroon">s1</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">t1</font> )
 </span>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="2_1_1_1_1"><b>suppose </b></a><a NAME="E1:2_1_1_1_1"/>
<font color="Maroon">s1</font> <a href="hidden.html#R1">=</a> <font color="Maroon">t1</font>
 ;<br/><div class="add"><a NAME="E2:2_1_1_1_1"/><b>then </b>
<span class="p1"><a href="borsuk_1.html#K7">[</a><span class="default"><font color="Maroon">s2</font>,<font color="Maroon">t1</font></span><a href="borsuk_1.html#K7">]</a></span> <a href="hidden.html#R2">in</a>  <a href="brouwer.html#K1" target="_self">DiffElems</a> <font color="Maroon">S</font>,<font color="Maroon">T</font>
 <b>by </b><i/>;<br/><b>hence </b><a NAME="E3:2_1_1_1_1"/>
not  <a href="brouwer.html#K1" target="_self">DiffElems</a> <font color="Maroon">S</font>,<font color="Maroon">T</font> is <a href="xboole_0.html#V1">empty</a>
 ;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="2_1_1_1_2"><b>suppose </b></a><a NAME="E1:2_1_1_1_2"/>
<font color="Maroon">s1</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">t1</font>
 ;<br/><div class="add"><a NAME="E2:2_1_1_1_2"/><b>then </b>
<span class="p1"><a href="borsuk_1.html#K7">[</a><span class="default"><font color="Maroon">s1</font>,<font color="Maroon">t1</font></span><a href="borsuk_1.html#K7">]</a></span> <a href="hidden.html#R2">in</a>  <a href="brouwer.html#K1" target="_self">DiffElems</a> <font color="Maroon">S</font>,<font color="Maroon">T</font>
 ;<br/><b>hence </b><a NAME="E3:2_1_1_1_2"/>
not  <a href="brouwer.html#K1" target="_self">DiffElems</a> <font color="Maroon">S</font>,<font color="Maroon">T</font> is <a href="xboole_0.html#V1">empty</a>
 ;<br/></div><b>end;</b></div></div><b>end;</b></div>

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