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<b>let </b><font color="Maroon">c<sub>1</sub></font>, <font color="Maroon">c<sub>2</sub></font> be   <a href="zf_lang.html#NM2">ZF-formula</a>;<br/>



<b>assume </b><a NAME="E1:73"/>
<font color="Maroon">c<sub>1</sub></font> is <a href="zf_lang.html#V4" target="_self">negative</a>
 ;<br/>

<a NAME="E2:73"/><b>then </b>
<font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#R1">=</a>  <a href="zf_lang.html#K6" target="_self">'not'</a> <span class="p1">(<span class="default"><a href="zf_lang.html#K20" target="_self">the_argument_of</a> <font color="Maroon">c<sub>1</sub></font></span>)</span>
 
<b>by </b><i><a class="ref" href="zf_lang.html#D30" target="_self">Def30</a></i>;<br/>
<b>hence </b><a NAME="E3:73"/>
( <font color="Maroon">c<sub>2</sub></font> <a href="zf_lang.html#R1" target="_self">is_immediate_constituent_of</a> <font color="Maroon">c<sub>1</sub></font> iff <font color="Maroon">c<sub>2</sub></font> <a href="hidden.html#R1">=</a>  <a href="zf_lang.html#K20" target="_self">the_argument_of</a> <font color="Maroon">c<sub>1</sub></font> )
 <b>by </b><i><a class="ref" href="zf_lang.html#T71" target="_self">Th71</a></i>;<br/>


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