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

<b>let </b><font color="Maroon">c<sub>1</sub></font>, <font color="Maroon">c<sub>2</sub></font>, <font color="Maroon">c<sub>3</sub></font>, <font color="Maroon">c<sub>4</sub></font> be   <a href="zf_lang.html#NM2">ZF-formula</a>;<br/>







<b>assume </b><a NAME="E1:48"/><i><font color="Green">E35</font></i>: 
<font color="Maroon">c<sub>1</sub></font> <a href="zf_lang.html#K12" target="_self">&lt;=&gt;</a> <font color="Maroon">c<sub>2</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>3</sub></font> <a href="zf_lang.html#K12" target="_self">&lt;=&gt;</a> <font color="Maroon">c<sub>4</sub></font>
 ;<br/>

<a NAME="E2:48"/>
<font color="Maroon">c<sub>1</sub></font> <a href="zf_lang.html#K11" target="_self">=&gt;</a> <font color="Maroon">c<sub>2</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>3</sub></font> <a href="zf_lang.html#K11" target="_self">=&gt;</a> <font color="Maroon">c<sub>4</sub></font>
 
<b>by </b><i><a class="txt" href="zf_lang.html#E1:48"><i><font color="Green">E35</font></i></a>, <a class="ref" href="zf_lang.html#T47" target="_self">Th47</a></i>;<br/>
<b>hence </b><a NAME="E3:48"/>
( <font color="Maroon">c<sub>1</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>3</sub></font> &amp; <font color="Maroon">c<sub>2</sub></font> <a href="hidden.html#R1">=</a> <font color="Maroon">c<sub>4</sub></font> )
 <b>by </b><i><a class="ref" href="zf_lang.html#T49" target="_self">Th49</a></i>;<br/>


</div>
