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<b>let </b><font color="Maroon">x</font> be   <a href="qc_lang1.html#NM3">bound_QC-variable</a>;<br/><b>let </b><font color="Maroon">p</font> be   <a href="qc_lang1.html#NM8">QC-formula</a>;<br/>



<a NAME="E1:26"/>
 <a href="qc_lang2.html#K5">Ex</a> <font color="Maroon">x</font>,<font color="Maroon">p</font> <a href="hidden.html#R1">=</a>  <a href="qc_lang1.html#K12">'not'</a> <span class="p1">(<span class="default"><a href="qc_lang1.html#K14">All</a> <font color="Maroon">x</font>,<span class="p2">(<span class="default"><a href="qc_lang1.html#K12">'not'</a> <font color="Maroon">p</font></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="qc_lang2.html#D5">QC_LANG2:def 5</a></i>;<br/>
<b>hence </b> <a href="qc_lang1.html#K23">still_not-bound_in</a> <span class="p1">(<span class="default"><a href="qc_lang2.html#K5">Ex</a> <font color="Maroon">x</font>,<font color="Maroon">p</font></span>)</span> = 
 <a href="qc_lang1.html#K23">still_not-bound_in</a> <span class="p1">(<span class="default"><a href="qc_lang1.html#K14">All</a> <font color="Maroon">x</font>,<span class="p2">(<span class="default"><a href="qc_lang1.html#K12">'not'</a> <font color="Maroon">p</font></span>)</span></span>)</span>
<b>by </b><i/>
<br/>.= 
<span class="p1">(<span class="default"><a href="qc_lang1.html#K23">still_not-bound_in</a> <span class="p2">(<span class="default"><a href="qc_lang1.html#K12">'not'</a> <font color="Maroon">p</font></span>)</span></span>)</span> <a href="subset_1.html#K7">\</a> <span class="p1"><a href="tarski.html#K1">{</a><span class="default"><font color="Maroon">x</font></span><a href="tarski.html#K1">}</a></span>
<b>by </b><i/>
<br/>.= 
<span class="p1">(<span class="default"><a href="qc_lang1.html#K23">still_not-bound_in</a> <font color="Maroon">p</font></span>)</span> <a href="subset_1.html#K7">\</a> <span class="p1"><a href="tarski.html#K1">{</a><span class="default"><font color="Maroon">x</font></span><a href="tarski.html#K1">}</a></span>
<b>by </b><i/>
;<br/><br/>


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