<?xml version="1.0"?>
<div class="add">

<b>let </b><font color="Maroon">c<sub>1</sub></font> be   <a href="zf_lang.html#NM2">ZF-formula</a>;<br/><b>let </b><font color="Maroon">c<sub>2</sub></font>, <font color="Maroon">c<sub>3</sub></font> be   <a href="zf_lang.html#NM1">Variable</a>;<br/>





<b>assume </b><a NAME="E1:178"/>
<font color="Maroon">c<sub>1</sub></font> is <a href="zf_lang.html#V8">disjunctive</a>
 ;<br/>

<a NAME="E2:178"/><b>then </b>
( <font color="Maroon">c<sub>1</sub></font> <a href="zf_lang1.html#K6" target="_self">/</a> <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>3</sub></font> is <a href="zf_lang.html#V8">disjunctive</a> &amp; <font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><a href="zf_lang.html#K21">the_left_argument_of</a> <font color="Maroon">c<sub>1</sub></font></span>)</span> <a href="zf_lang.html#K10">'or'</a> <span class="p1">(<span class="default"><a href="zf_lang.html#K22">the_right_argument_of</a> <font color="Maroon">c<sub>1</sub></font></span>)</span> )
 
<b>by </b><i><a class="ref" href="zf_lang1.html#T188" target="_self">Th188</a>, <a class="ref" href="zf_lang.html#T59">ZF_LANG:59</a></i>;<br/>
<a NAME="E3:178"/><b>then </b>
( <font color="Maroon">c<sub>1</sub></font> <a href="zf_lang1.html#K6" target="_self">/</a> <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>3</sub></font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><a href="zf_lang.html#K21">the_left_argument_of</a> <span class="p2">(<span class="default"><font color="Maroon">c<sub>1</sub></font> <a href="zf_lang1.html#K6" target="_self">/</a> <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>3</sub></font></span>)</span></span>)</span> <a href="zf_lang.html#K10">'or'</a> <span class="p1">(<span class="default"><a href="zf_lang.html#K22">the_right_argument_of</a> <span class="p2">(<span class="default"><font color="Maroon">c<sub>1</sub></font> <a href="zf_lang1.html#K6" target="_self">/</a> <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>3</sub></font></span>)</span></span>)</span> &amp; <font color="Maroon">c<sub>1</sub></font> <a href="zf_lang1.html#K6" target="_self">/</a> <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>3</sub></font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="zf_lang.html#K21">the_left_argument_of</a> <font color="Maroon">c<sub>1</sub></font></span>)</span> <a href="zf_lang1.html#K6" target="_self">/</a> <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>3</sub></font></span>)</span> <a href="zf_lang.html#K10">'or'</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="zf_lang.html#K22">the_right_argument_of</a> <font color="Maroon">c<sub>1</sub></font></span>)</span> <a href="zf_lang1.html#K6" target="_self">/</a> <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>3</sub></font></span>)</span> )
 
<b>by </b><i><a class="ref" href="zf_lang1.html#T175" target="_self">Th175</a>, <a class="ref" href="zf_lang.html#T59">ZF_LANG:59</a></i>;<br/>
<b>hence </b><a NAME="E4:178"/>
(  <a href="zf_lang.html#K21">the_left_argument_of</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>1</sub></font> <a href="zf_lang1.html#K6" target="_self">/</a> <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>3</sub></font></span>)</span> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><a href="zf_lang.html#K21">the_left_argument_of</a> <font color="Maroon">c<sub>1</sub></font></span>)</span> <a href="zf_lang1.html#K6" target="_self">/</a> <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>3</sub></font> &amp;  <a href="zf_lang.html#K22">the_right_argument_of</a> <span class="p1">(<span class="default"><font color="Maroon">c<sub>1</sub></font> <a href="zf_lang1.html#K6" target="_self">/</a> <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>3</sub></font></span>)</span> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><a href="zf_lang.html#K22">the_right_argument_of</a> <font color="Maroon">c<sub>1</sub></font></span>)</span> <a href="zf_lang1.html#K6" target="_self">/</a> <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>3</sub></font> )
 <b>by </b><i><a class="ref" href="zf_lang.html#T48">ZF_LANG:48</a></i>;<br/>


</div>
