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

<b>let </b><font color="Maroon">x0</font> be   <a href="real_1.html#NM1">Real</a>;<br/><b>let </b><font color="Maroon">x1</font> be   <a href="real_1.html#NM1">Real</a>;<br/><b>let </b><font color="Maroon">f</font> be   <a href="funct_2.html#NM1">Function</a> of  <a href="numbers.html#K1">REAL</a> , <a href="numbers.html#K1">REAL</a> ;<br/>





<b>assume </b><a NAME="E1:46"/><i><font color="Green">E40</font></i>: 
<font color="Maroon">x0</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> <font color="Maroon">x1</font>
 ;<br/>

<b>then </b><span class="p1"><a href="diff_1.html#K12" target="_self">[!</a><span class="default"><font color="Maroon">f</font>,<font color="Maroon">x0</font>,<font color="Maroon">x1</font></span><a href="diff_1.html#K12" target="_self">!]</a></span> = 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><font color="Maroon">f</font> <a href="seq_1.html#K2">.</a> <font color="Maroon">x0</font></span>)</span> <a href="real_1.html#K5">-</a> <span class="p2">(<span class="default"><font color="Maroon">f</font> <a href="seq_1.html#K2">.</a> <font color="Maroon">x1</font></span>)</span></span>)</span> <a href="real_1.html#K6">/</a> <span class="p1">(<span class="default"><font color="Maroon">x0</font> <a href="real_1.html#K5">-</a> <font color="Maroon">x1</font></span>)</span>
<b>by </b><i/>
<br/>.= 
<span class="p1">(<span class="default"><a href="real_1.html#K1">-</a> <span class="p2">(<span class="default"><span class="p3">(<span class="default"><font color="Maroon">f</font> <a href="seq_1.html#K2">.</a> <font color="Maroon">x1</font></span>)</span> <a href="real_1.html#K5">-</a> <span class="p3">(<span class="default"><font color="Maroon">f</font> <a href="seq_1.html#K2">.</a> <font color="Maroon">x0</font></span>)</span></span>)</span></span>)</span> <a href="real_1.html#K6">/</a> <span class="p1">(<span class="default"><a href="real_1.html#K1">-</a> <span class="p2">(<span class="default"><font color="Maroon">x1</font> <a href="real_1.html#K5">-</a> <font color="Maroon">x0</font></span>)</span></span>)</span>

<br/>.= 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><font color="Maroon">f</font> <a href="seq_1.html#K2">.</a> <font color="Maroon">x1</font></span>)</span> <a href="real_1.html#K5">-</a> <span class="p2">(<span class="default"><font color="Maroon">f</font> <a href="seq_1.html#K2">.</a> <font color="Maroon">x0</font></span>)</span></span>)</span> <a href="real_1.html#K6">/</a> <span class="p1">(<span class="default"><font color="Maroon">x1</font> <a href="real_1.html#K5">-</a> <font color="Maroon">x0</font></span>)</span>
<b>by </b><i><a class="ref" href="xcmplx_1.html#T192">XCMPLX_1:192</a></i>
<br/>.= 
<span class="p1"><a href="diff_1.html#K12" target="_self">[!</a><span class="default"><font color="Maroon">f</font>,<font color="Maroon">x1</font>,<font color="Maroon">x0</font></span><a href="diff_1.html#K12" target="_self">!]</a></span>
<b>by </b><i>, </i>
;<br/>
<b>hence </b><a NAME="E3:46"/>
<span class="p1"><a href="diff_1.html#K12" target="_self">[!</a><span class="default"><font color="Maroon">f</font>,<font color="Maroon">x0</font>,<font color="Maroon">x1</font></span><a href="diff_1.html#K12" target="_self">!]</a></span> <a href="hidden.html#R1">=</a> <span class="p1"><a href="diff_1.html#K12" target="_self">[!</a><span class="default"><font color="Maroon">f</font>,<font color="Maroon">x1</font>,<font color="Maroon">x0</font></span><a href="diff_1.html#K12" target="_self">!]</a></span>
 ;<br/>


</div>
