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<b>let </b><font color="Maroon">p</font> be   <a href="zf_lang.html#NM2">ZF-formula</a>;<br/><b>let </b><font color="Maroon">x</font> be   <a href="zf_lang.html#NM1">Variable</a>;<br/>



<a NAME="E1:9"/>
 <a href="zf_lang.html#K13">Ex</a> <font color="Maroon">x</font>,<font color="Maroon">p</font> is <a href="zf_lang.html#V11">existential</a>
 
<b>by </b><i><a class="ref" href="zf_lang.html#T22">ZF_LANG:22</a></i>;<br/>
<a NAME="E2:9"/><b>then </b>
 <a href="zf_lang.html#K13">Ex</a> <font color="Maroon">x</font>,<font color="Maroon">p</font> <a href="hidden.html#R1">=</a>  <a href="zf_lang.html#K13">Ex</a> <span class="p1">(<span class="default"><a href="zf_lang.html#K23">bound_in</a> <span class="p2">(<span class="default"><a href="zf_lang.html#K13">Ex</a> <font color="Maroon">x</font>,<font color="Maroon">p</font></span>)</span></span>)</span>,<span class="p1">(<span class="default"><a href="zf_lang.html#K24">the_scope_of</a> <span class="p2">(<span class="default"><a href="zf_lang.html#K13">Ex</a> <font color="Maroon">x</font>,<font color="Maroon">p</font></span>)</span></span>)</span>
 
<b>by </b><i><a class="ref" href="zf_lang.html#T63">ZF_LANG:63</a></i>;<br/>
<b>hence </b><a NAME="E3:9"/>
(  <a href="zf_lang.html#K23">bound_in</a> <span class="p1">(<span class="default"><a href="zf_lang.html#K13">Ex</a> <font color="Maroon">x</font>,<font color="Maroon">p</font></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">x</font> &amp;  <a href="zf_lang.html#K24">the_scope_of</a> <span class="p1">(<span class="default"><a href="zf_lang.html#K13">Ex</a> <font color="Maroon">x</font>,<font color="Maroon">p</font></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">p</font> )
 <b>by </b><i><a class="ref" href="zf_lang.html#T51">ZF_LANG:51</a></i>;<br/>


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