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

<b>let </b><font color="Maroon">a</font> be    <a href="subset_1.html#M1">Element</a> of  <a href="numbers.html#K1">REAL</a> ;<br/><b>let </b><font color="Maroon">b</font> be    <a href="subset_1.html#M1">Element</a> of  <a href="numbers.html#K1">REAL</a> ;<br/><b>let </b><font color="Maroon">c</font> be    <a href="subset_1.html#M1">Element</a> of  <a href="numbers.html#K1">REAL</a> ;<br/><b>let </b><font color="Maroon">d</font> be    <a href="subset_1.html#M1">Element</a> of  <a href="numbers.html#K1">REAL</a> ;<br/>







<b>reconsider </b><font color="Maroon">a'</font> = <font color="Maroon">a</font>, <font color="Maroon">b'</font> = <font color="Maroon">b</font>, <font color="Maroon">c'</font> = <font color="Maroon">c</font>, <font color="Maroon">d'</font> = <font color="Maroon">d</font> as    <a href="subset_1.html#M1">Element</a> of  <a href="numbers.html#K1">REAL</a>  ;<br/>
<b>thus </b><a NAME="E2:49"/>
 <a href="quaterni.html#K17" target="_self">Rea</a> <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">a</font>
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="49_1"><b>proof </b></a><div class="add">

<div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_1_1"><b>per </b></a><a class="txt" onclick="hs(this)" href="javascript:()"><b>cases </b></a><span class="hide"><a NAME="E1:49_1_1"/>
( ( <font color="Maroon">c</font> <a href="hidden.html#R1">=</a> 0 &amp; <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> 0 ) or <font color="Maroon">c</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 or <font color="Maroon">d</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 )
 </span>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_1_1_1"><b>suppose </b></a><a NAME="E1:49_1_1_1"/>
( <font color="Maroon">c</font> <a href="hidden.html#R1">=</a> 0 &amp; <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> 0 )
 ;<br/><div class="add"><a NAME="E2:49_1_1_1"/><b>then </b><i><font color="Green">E37</font></i>: 
<span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <span class="p1"><a href="arytm_0.html#K5">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font></span><a href="arytm_0.html#K5">*]</a></span>
 <b>by </b><i/>;<br/><a NAME="E3:49_1_1_1"/>
 <a href="complex1.html#K3">Re</a> <span class="p1"><a href="arytm_0.html#K5">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font></span><a href="arytm_0.html#K5">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">a</font>
 <b>by </b><i/>;<br/><b>hence </b><a NAME="E4:49_1_1_1"/>
 <a href="quaterni.html#K17" target="_self">Rea</a> <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">a</font>
 <b>by </b><i>, </i>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_1_1_2"><b>suppose </b></a><a NAME="E1:49_1_1_2"/>
( <font color="Maroon">c</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 or <font color="Maroon">d</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 )
 ;<br/><div class="add"><a NAME="E2:49_1_1_2"/><b>then </b><i><font color="Green">E40</font></i>: 
<span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> 0,1,2,3 <a href="quaterni.html#K3" target="_self">--&gt;</a> <font color="Maroon">a'</font>,<font color="Maroon">b'</font>,<font color="Maroon">c'</font>,<font color="Maroon">d'</font>
 <b>by </b><i/>;<br/><b>then reconsider </b><font color="Maroon">f</font> = <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> as   <a href="funct_2.html#NM1">Function</a> of 4, <a href="numbers.html#K1">REAL</a>  <b>by </b><i><a class="ref" href="card_1.html#T90">CARD_1:90</a></i>;<br/><a NAME="E4:49_1_1_2"/><i><font color="Green">E41</font></i>: 
not <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R2">in</a>  <a href="numbers.html#K2">COMPLEX</a> 
 <b>by </b><i>, </i>;<br/><a NAME="E5:49_1_1_2"/>
<font color="Maroon">f</font> <a href="seq_1.html#K2">.</a> 0 <a href="hidden.html#R1">=</a> <font color="Maroon">a</font>
 <b>by </b><i>, , </i>;<br/><b>hence </b><a NAME="E6:49_1_1_2"/>
 <a href="quaterni.html#K17" target="_self">Rea</a> <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">a</font>
 <b>by </b><i>, </i>;<br/></div><b>end;</b></div></div><b>end;</b></div>

</div><b>end;</b></div>

<b>thus </b><a NAME="E3:49"/>
 <a href="quaterni.html#K18" target="_self">Im1</a> <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">b</font>
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="49_2"><b>proof </b></a><div class="add">

<div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_2_1"><b>per </b></a><a class="txt" onclick="hs(this)" href="javascript:()"><b>cases </b></a><span class="hide"><a NAME="E1:49_2_1"/>
( ( <font color="Maroon">c</font> <a href="hidden.html#R1">=</a> 0 &amp; <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> 0 ) or <font color="Maroon">c</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 or <font color="Maroon">d</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 )
 </span>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_2_1_1"><b>suppose </b></a><a NAME="E1:49_2_1_1"/>
( <font color="Maroon">c</font> <a href="hidden.html#R1">=</a> 0 &amp; <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> 0 )
 ;<br/><div class="add"><a NAME="E2:49_2_1_1"/><b>then </b><i><font color="Green">E42</font></i>: 
<span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <span class="p1"><a href="arytm_0.html#K5">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font></span><a href="arytm_0.html#K5">*]</a></span>
 <b>by </b><i/>;<br/><a NAME="E3:49_2_1_1"/>
 <a href="complex1.html#K4">Im</a> <span class="p1"><a href="arytm_0.html#K5">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font></span><a href="arytm_0.html#K5">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">b</font>
 <b>by </b><i/>;<br/><b>hence </b><a NAME="E4:49_2_1_1"/>
 <a href="quaterni.html#K18" target="_self">Im1</a> <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">b</font>
 <b>by </b><i>, </i>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_2_1_2"><b>suppose </b></a><a NAME="E1:49_2_1_2"/>
( <font color="Maroon">c</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 or <font color="Maroon">d</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 )
 ;<br/><div class="add"><a NAME="E2:49_2_1_2"/><b>then </b><i><font color="Green">E43</font></i>: 
<span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> 0,1,2,3 <a href="quaterni.html#K3" target="_self">--&gt;</a> <font color="Maroon">a'</font>,<font color="Maroon">b'</font>,<font color="Maroon">c'</font>,<font color="Maroon">d'</font>
 <b>by </b><i/>;<br/><b>then reconsider </b><font color="Maroon">f</font> = <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> as   <a href="funct_2.html#NM1">Function</a> of 4, <a href="numbers.html#K1">REAL</a>  <b>by </b><i><a class="ref" href="card_1.html#T90">CARD_1:90</a></i>;<br/><a NAME="E4:49_2_1_2"/><i><font color="Green">E44</font></i>: 
not <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R2">in</a>  <a href="numbers.html#K2">COMPLEX</a> 
 <b>by </b><i>, </i>;<br/><a NAME="E5:49_2_1_2"/>
<font color="Maroon">f</font> <a href="seq_1.html#K2">.</a> 1 <a href="hidden.html#R1">=</a> <font color="Maroon">b</font>
 <b>by </b><i>, , </i>;<br/><b>hence </b><a NAME="E6:49_2_1_2"/>
 <a href="quaterni.html#K18" target="_self">Im1</a> <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">b</font>
 <b>by </b><i>, </i>;<br/></div><b>end;</b></div></div><b>end;</b></div>

</div><b>end;</b></div>

<b>thus </b><a NAME="E4:49"/>
 <a href="quaterni.html#K19" target="_self">Im2</a> <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">c</font>
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="49_3"><b>proof </b></a><div class="add">

<div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_3_1"><b>per </b></a><a class="txt" onclick="hs(this)" href="javascript:()"><b>cases </b></a><span class="hide"><a NAME="E1:49_3_1"/>
( ( <font color="Maroon">c</font> <a href="hidden.html#R1">=</a> 0 &amp; <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> 0 ) or <font color="Maroon">c</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 or <font color="Maroon">d</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 )
 </span>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_3_1_1"><b>suppose </b></a><a NAME="E1:49_3_1_1"/><i><font color="Green">E68</font></i>: 
( <font color="Maroon">c</font> <a href="hidden.html#R1">=</a> 0 &amp; <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> 0 )
 ;<br/><div class="add"><a NAME="E2:49_3_1_1"/><b>then </b>
<span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <span class="p1"><a href="arytm_0.html#K5">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font></span><a href="arytm_0.html#K5">*]</a></span>
 <b>by </b><i/>;<br/><b>hence </b><a NAME="E3:49_3_1_1"/>
 <a href="quaterni.html#K19" target="_self">Im2</a> <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">c</font>
 <b>by </b><i>, </i>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_3_1_2"><b>suppose </b></a><a NAME="E1:49_3_1_2"/>
( <font color="Maroon">c</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 or <font color="Maroon">d</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 )
 ;<br/><div class="add"><a NAME="E2:49_3_1_2"/><b>then </b><i><font color="Green">E69</font></i>: 
<span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> 0,1,2,3 <a href="quaterni.html#K3" target="_self">--&gt;</a> <font color="Maroon">a'</font>,<font color="Maroon">b'</font>,<font color="Maroon">c'</font>,<font color="Maroon">d'</font>
 <b>by </b><i/>;<br/><b>then reconsider </b><font color="Maroon">f</font> = <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> as   <a href="funct_2.html#NM1">Function</a> of 4, <a href="numbers.html#K1">REAL</a>  <b>by </b><i><a class="ref" href="card_1.html#T90">CARD_1:90</a></i>;<br/><a NAME="E4:49_3_1_2"/><i><font color="Green">E70</font></i>: 
not <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R2">in</a>  <a href="numbers.html#K2">COMPLEX</a> 
 <b>by </b><i>, </i>;<br/><a NAME="E5:49_3_1_2"/>
<font color="Maroon">f</font> <a href="seq_1.html#K2">.</a> 2 <a href="hidden.html#R1">=</a> <font color="Maroon">c</font>
 <b>by </b><i>, , </i>;<br/><b>hence </b><a NAME="E6:49_3_1_2"/>
 <a href="quaterni.html#K19" target="_self">Im2</a> <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">c</font>
 <b>by </b><i>, </i>;<br/></div><b>end;</b></div></div><b>end;</b></div>

</div><b>end;</b></div>

<div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_4"><b>per </b></a><a class="txt" onclick="hs(this)" href="javascript:()"><b>cases </b></a><span class="hide"><a NAME="E1:49_4"/>
( ( <font color="Maroon">c</font> <a href="hidden.html#R1">=</a> 0 &amp; <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> 0 ) or <font color="Maroon">c</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 or <font color="Maroon">d</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 )
 </span>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_4_1"><b>suppose </b></a><a NAME="E1:49_4_1"/><i><font color="Green">E71</font></i>: 
( <font color="Maroon">c</font> <a href="hidden.html#R1">=</a> 0 &amp; <font color="Maroon">d</font> <a href="hidden.html#R1">=</a> 0 )
 ;<br/><div class="add"><a NAME="E2:49_4_1"/><b>then </b>
<span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <span class="p1"><a href="arytm_0.html#K5">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font></span><a href="arytm_0.html#K5">*]</a></span>
 <b>by </b><i/>;<br/><b>hence </b><a NAME="E3:49_4_1"/>
 <a href="quaterni.html#K20" target="_self">Im3</a> <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">d</font>
 <b>by </b><i>, </i>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="49_4_2"><b>suppose </b></a><a NAME="E1:49_4_2"/>
( <font color="Maroon">c</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 or <font color="Maroon">d</font> <a href="hidden.html#NR2" target="_self">&lt;&gt;</a> 0 )
 ;<br/><div class="add"><a NAME="E2:49_4_2"/><b>then </b><i><font color="Green">E72</font></i>: 
<span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> 0,1,2,3 <a href="quaterni.html#K3" target="_self">--&gt;</a> <font color="Maroon">a'</font>,<font color="Maroon">b'</font>,<font color="Maroon">c'</font>,<font color="Maroon">d'</font>
 <b>by </b><i/>;<br/><b>then reconsider </b><font color="Maroon">f</font> = <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> as   <a href="funct_2.html#NM1">Function</a> of 4, <a href="numbers.html#K1">REAL</a>  <b>by </b><i><a class="ref" href="card_1.html#T90">CARD_1:90</a></i>;<br/><a NAME="E4:49_4_2"/><i><font color="Green">E73</font></i>: 
not <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R2">in</a>  <a href="numbers.html#K2">COMPLEX</a> 
 <b>by </b><i>, </i>;<br/><a NAME="E5:49_4_2"/>
<font color="Maroon">f</font> <a href="seq_1.html#K2">.</a> 3 <a href="hidden.html#R1">=</a> <font color="Maroon">d</font>
 <b>by </b><i>, , </i>;<br/><b>hence </b><a NAME="E6:49_4_2"/>
 <a href="quaterni.html#K20" target="_self">Im3</a> <span class="p1"><a href="quaterni.html#K6" target="_self">[*</a><span class="default"><font color="Maroon">a</font>,<font color="Maroon">b</font>,<font color="Maroon">c</font>,<font color="Maroon">d</font></span><a href="quaterni.html#K6" target="_self">*]</a></span> <a href="hidden.html#R1">=</a> <font color="Maroon">d</font>
 <b>by </b><i>, </i>;<br/></div><b>end;</b></div></div><b>end;</b></div>

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