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<b>let </b><font color="Maroon">A</font> be  non <a href="struct_0.html#V3">empty</a> <a href="orders_2.html#NM1">Poset</a>;<br/><b>let </b><font color="Maroon">f</font> be    <a href="orders_1.html#M1">Choice_Function</a> of  <a href="orders_1.html#K1">BOOL</a> the <a href="struct_0.html#U1">carrier</a> of <font color="Maroon">A</font>;<br/>



<a NAME="E1:67"/>
<span class="p1"><a href="tarski.html#K1">{</a><span class="default"><span class="p2">(<span class="default"><font color="Maroon">f</font> <a href="funct_1.html#K1">.</a> the <a href="struct_0.html#U1">carrier</a> of <font color="Maroon">A</font></span>)</span></span><a href="tarski.html#K1">}</a></span> is    <a href="orders_2.html#M2" target="_self">Chain</a> of <font color="Maroon">f</font>
 
<b>by </b><i><a class="ref" href="orders_2.html#T32" target="_self">Th32</a></i>;<br/>
<a NAME="E2:67"/><b>then </b>
( <span class="p1"><a href="tarski.html#K1">{</a><span class="default"><span class="p2">(<span class="default"><font color="Maroon">f</font> <a href="funct_1.html#K1">.</a> the <a href="struct_0.html#U1">carrier</a> of <font color="Maroon">A</font></span>)</span></span><a href="tarski.html#K1">}</a></span> <a href="hidden.html#R2">in</a>  <a href="orders_2.html#K4" target="_self">Chains</a> <font color="Maroon">f</font> &amp; <span class="p1"><a href="tarski.html#K1">{</a><span class="default"><span class="p2">(<span class="default"><font color="Maroon">f</font> <a href="funct_1.html#K1">.</a> the <a href="struct_0.html#U1">carrier</a> of <font color="Maroon">A</font></span>)</span></span><a href="tarski.html#K1">}</a></span> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="xboole_0.html#K1">{}</a>  )
 
<b>by </b><i/>;<br/>
<b>hence </b><a NAME="E3:67"/>
 <a href="tarski.html#K3">union</a> <span class="p1">(<span class="default"><a href="orders_2.html#K4" target="_self">Chains</a> <font color="Maroon">f</font></span>)</span> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a>  <a href="xboole_0.html#K1">{}</a> 
 <b>by </b><i><a class="ref" href="orders_1.html#T91">ORDERS_1:91</a></i>;<br/>


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