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<b>let </b><font color="Maroon">H1</font> be   <a href="zf_lang.html#NM2">ZF-formula</a>;<br/><b>let </b><font color="Maroon">H2</font> be   <a href="zf_lang.html#NM2">ZF-formula</a>;<br/>



<b>thus </b> <a href="zf_lang1.html#K3" target="_self">variables_in</a> <span class="p1">(<span class="default"><font color="Maroon">H1</font> <a href="zf_lang.html#K10">'or'</a> <font color="Maroon">H2</font></span>)</span> = 
 <a href="zf_lang1.html#K3" target="_self">variables_in</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="zf_lang.html#K6">'not'</a> <font color="Maroon">H1</font></span>)</span> <a href="zf_lang.html#K7">'&amp;'</a> <span class="p2">(<span class="default"><a href="zf_lang.html#K6">'not'</a> <font color="Maroon">H2</font></span>)</span></span>)</span>
<b>by </b><i><a class="ref" href="zf_lang1.html#T16" target="_self">Th16</a></i>
<br/>.= 
<span class="p1">(<span class="default"><a href="zf_lang1.html#K3" target="_self">variables_in</a> <span class="p2">(<span class="default"><a href="zf_lang.html#K6">'not'</a> <font color="Maroon">H1</font></span>)</span></span>)</span> <a href="xboole_0.html#K2">\/</a> <span class="p1">(<span class="default"><a href="zf_lang1.html#K3" target="_self">variables_in</a> <span class="p2">(<span class="default"><a href="zf_lang.html#K6">'not'</a> <font color="Maroon">H2</font></span>)</span></span>)</span>
<b>by </b><i/>
<br/>.= 
<span class="p1">(<span class="default"><a href="zf_lang1.html#K3" target="_self">variables_in</a> <font color="Maroon">H1</font></span>)</span> <a href="xboole_0.html#K2">\/</a> <span class="p1">(<span class="default"><a href="zf_lang1.html#K3" target="_self">variables_in</a> <span class="p2">(<span class="default"><a href="zf_lang.html#K6">'not'</a> <font color="Maroon">H2</font></span>)</span></span>)</span>
<b>by </b><i><a class="ref" href="zf_lang1.html#T16" target="_self">Th16</a></i>
<br/>.= 
<span class="p1">(<span class="default"><a href="zf_lang1.html#K3" target="_self">variables_in</a> <font color="Maroon">H1</font></span>)</span> <a href="xboole_0.html#K2">\/</a> <span class="p1">(<span class="default"><a href="zf_lang1.html#K3" target="_self">variables_in</a> <font color="Maroon">H2</font></span>)</span>
<b>by </b><i><a class="ref" href="zf_lang1.html#T16" target="_self">Th16</a></i>
;<br/>


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