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

<b>let </b><font color="Maroon" title="c2">t1</font>, <font color="Maroon" title="c3">t2</font> be  <a href="finset_1.html#V1" title="FINSET_1:attr.1">finite</a> <a href="trees_2.html#NM6" title="TREES_2:NM.6">DecoratedTree</a> of  <a href="qc_lang1.html#K8" title="QC_LANG1:func.8">QC-WFF</a> ;<br/>

<b>assume </b><b>that </b><br/><a NAME="E1:32_1_2"/><i><font color="Green" title="E28">A6</font></i>: 
( <font color="Maroon" title="c2">t1</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c1">p</font> &amp; ( for <font color="Olive" title="b1">x</font> being   <a href="trees_1.html#M1" title="TREES_1:mode.1">Element</a> of  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c2">t1</font> holds   <a href="trees_9.html#K2" title="TREES_9:func.2">succ</a> <font color="Maroon" title="c2">t1</font>,<font color="Olive" title="b1">x</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="qc_lang4.html#K1" title="QC_LANG4:func.1">list_of_immediate_constituents</a> <span class="p1">(<span class="default"><font color="Maroon" title="c2">t1</font> <a href="trees_2.html#K3" title="TREES_2:func.3">.</a> <font color="Olive" title="b1">x</font></span>)</span> ) )
 <b>and </b><br/><a NAME="E2:32_1_2"/><i><font color="Green" title="E29">A7</font></i>: 
( <font color="Maroon" title="c3">t2</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c1">p</font> &amp; ( for <font color="Olive" title="b1">x</font> being   <a href="trees_1.html#M1" title="TREES_1:mode.1">Element</a> of  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c3">t2</font> holds   <a href="trees_9.html#K2" title="TREES_9:func.2">succ</a> <font color="Maroon" title="c3">t2</font>,<font color="Olive" title="b1">x</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="qc_lang4.html#K1" title="QC_LANG4:func.1">list_of_immediate_constituents</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">t2</font> <a href="trees_2.html#K3" title="TREES_2:func.3">.</a> <font color="Olive" title="b1">x</font></span>)</span> ) )
 ;<br/>

<a NAME="E3:32_1_2"/>
for <font color="Olive" title="b1">t1</font>, <font color="Olive" title="b2">t2</font> being <a href="finset_1.html#V1" title="FINSET_1:attr.1">finite</a> <a href="trees_2.html#NM6" title="TREES_2:NM.6">DecoratedTree</a> of  <a href="qc_lang1.html#K8" title="QC_LANG1:func.8">QC-WFF</a>   st <font color="Olive" title="b1">t1</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c1">p</font> &amp; ( for <font color="Olive" title="b3">x</font> being   <a href="trees_1.html#M1" title="TREES_1:mode.1">Element</a> of  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Olive" title="b1">t1</font> holds   <a href="trees_9.html#K2" title="TREES_9:func.2">succ</a> <font color="Olive" title="b1">t1</font>,<font color="Olive" title="b3">x</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="qc_lang4.html#K1" title="QC_LANG4:func.1">list_of_immediate_constituents</a> <span class="p1">(<span class="default"><font color="Olive" title="b1">t1</font> <a href="trees_2.html#K3" title="TREES_2:func.3">.</a> <font color="Olive" title="b3">x</font></span>)</span> ) &amp; <font color="Olive" title="b2">t2</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c1">p</font> &amp; ( for <font color="Olive" title="b3">x</font> being   <a href="trees_1.html#M1" title="TREES_1:mode.1">Element</a> of  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Olive" title="b2">t2</font> holds   <a href="trees_9.html#K2" title="TREES_9:func.2">succ</a> <font color="Olive" title="b2">t2</font>,<font color="Olive" title="b3">x</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="qc_lang4.html#K1" title="QC_LANG4:func.1">list_of_immediate_constituents</a> <span class="p1">(<span class="default"><font color="Olive" title="b2">t2</font> <a href="trees_2.html#K3" title="TREES_2:func.3">.</a> <font color="Olive" title="b3">x</font></span>)</span> ) holds <br/><font color="Olive" title="b1">t1</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Olive" title="b2">t2</font>
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="32_1_2_1"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon" title="c4">t1</font>, <font color="Maroon" title="c5">t2</font> be  <a href="finset_1.html#V1" title="FINSET_1:attr.1">finite</a> <a href="trees_2.html#NM6" title="TREES_2:NM.6">DecoratedTree</a> of  <a href="qc_lang1.html#K8" title="QC_LANG1:func.8">QC-WFF</a> ;<br/>

<b>assume </b><b>that </b><br/><a NAME="E1:32_1_2_1"/><i><font color="Green" title="E30">A8</font></i>: 
( <font color="Maroon" title="c4">t1</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c1">p</font> &amp; ( for <font color="Olive" title="b1">x</font> being   <a href="trees_1.html#M1" title="TREES_1:mode.1">Element</a> of  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c4">t1</font> holds   <a href="trees_9.html#K2" title="TREES_9:func.2">succ</a> <font color="Maroon" title="c4">t1</font>,<font color="Olive" title="b1">x</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="qc_lang4.html#K1" title="QC_LANG4:func.1">list_of_immediate_constituents</a> <span class="p1">(<span class="default"><font color="Maroon" title="c4">t1</font> <a href="trees_2.html#K3" title="TREES_2:func.3">.</a> <font color="Olive" title="b1">x</font></span>)</span> ) )
 <b>and </b><br/><a NAME="E2:32_1_2_1"/><i><font color="Green" title="E31">A9</font></i>: 
( <font color="Maroon" title="c5">t2</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c1">p</font> &amp; ( for <font color="Olive" title="b1">x</font> being   <a href="trees_1.html#M1" title="TREES_1:mode.1">Element</a> of  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c5">t2</font> holds   <a href="trees_9.html#K2" title="TREES_9:func.2">succ</a> <font color="Maroon" title="c5">t2</font>,<font color="Olive" title="b1">x</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="qc_lang4.html#K1" title="QC_LANG4:func.1">list_of_immediate_constituents</a> <span class="p1">(<span class="default"><font color="Maroon" title="c5">t2</font> <a href="trees_2.html#K3" title="TREES_2:func.3">.</a> <font color="Olive" title="b1">x</font></span>)</span> ) )
 ;<br/>

<b>defpred </b><font color="Maroon">S<sub>1</sub></font>[   <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a> ] <b>means </b>( $1 <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c5">t2</font> &amp; <font color="Maroon" title="c4">t1</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> $1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c5">t2</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> $1 );<br/>
<a NAME="E3:32_1_2_1"/><i><font color="Green" title="E32">A10</font></i>: 
<font color="Maroon">S<sub>1</sub></font>[ <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> ]
 
<b>by </b><i><a class="txt" href="qc_lang4.html#E1:32_1_2_1"><i><font color="Green" title="E30">A8</font></i></a>, <a class="txt" href="qc_lang4.html#E2:32_1_2_1"><i><font color="Green" title="E31">A9</font></i></a>, <a class="ref" href="trees_1.html#T47" title="TREES_1:th.47">TREES_1:47</a></i>;<br/>
<a NAME="E4:32_1_2_1"/><i><font color="Green" title="E33">A11</font></i>: 
for <font color="Olive" title="b1">t</font> being   <a href="trees_1.html#M1" title="TREES_1:mode.1">Element</a> of  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c4">t1</font><br/> for <font color="Olive" title="b2">n</font> being   <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of  <a href="numbers.html#K5" title="NUMBERS:func.5">NAT</a>   st <font color="Maroon">S<sub>1</sub></font>[<font color="Olive" title="b1">t</font>] &amp; <font color="Olive" title="b1">t</font> <a href="finseq_1.html#K8" title="FINSEQ_1:func.8">^</a> <span class="p1"><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">&lt;*</a><span class="default"><font color="Olive" title="b2">n</font></span><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">*&gt;</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c4">t1</font> holds <br/><font color="Maroon">S<sub>1</sub></font>[<font color="Olive" title="b1">t</font> <a href="finseq_1.html#K8" title="FINSEQ_1:func.8">^</a> <span class="p1"><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">&lt;*</a><span class="default"><font color="Olive" title="b2">n</font></span><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">*&gt;</a></span>]
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="32_1_2_1_1"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon" title="c6">t</font> be    <a href="trees_1.html#M1" title="TREES_1:mode.1">Element</a> of  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c4">t1</font>;<br/><b>let </b><font color="Maroon" title="c7">n</font> be    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of  <a href="numbers.html#K5" title="NUMBERS:func.5">NAT</a> ;<br/>



<b>assume </b><a NAME="E1:32_1_2_1_1"/><i><font color="Green" title="E34">A12</font></i>: 
( <font color="Maroon">S<sub>1</sub></font>[<font color="Maroon" title="c6">t</font>] &amp; <font color="Maroon" title="c6">t</font> <a href="finseq_1.html#K8" title="FINSEQ_1:func.8">^</a> <span class="p1"><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">&lt;*</a><span class="default"><font color="Maroon" title="c7">n</font></span><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">*&gt;</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c4">t1</font> )
 ;<br/>

<b>then reconsider </b><font color="Maroon" title="c8">t'</font> = <font color="Maroon" title="c6">t</font> as    <a href="trees_1.html#M1" title="TREES_1:mode.1">Element</a> of  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c5">t2</font> ;<br/>
<i><font color="Green" title="E35">A13</font></i>:  <a href="trees_9.html#K2" title="TREES_9:func.2">succ</a> <font color="Maroon" title="c4">t1</font>,<font color="Maroon" title="c6">t</font> = 
 <a href="qc_lang4.html#K1" title="QC_LANG4:func.1">list_of_immediate_constituents</a> <span class="p1">(<span class="default"><font color="Maroon" title="c5">t2</font> <a href="trees_2.html#K3" title="TREES_2:func.3">.</a> <font color="Maroon" title="c8">t'</font></span>)</span>
<b>by </b><i><a class="txt" href="qc_lang4.html#E1:32_1_2_1"><i><font color="Green" title="E30">A8</font></i></a>, <a class="txt" href="qc_lang4.html#E1:32_1_2_1_1"><i><font color="Green" title="E34">A12</font></i></a></i>
<br/>.= 
 <a href="trees_9.html#K2" title="TREES_9:func.2">succ</a> <font color="Maroon" title="c5">t2</font>,<font color="Maroon" title="c8">t'</font>
<b>by </b><i><a class="txt" href="qc_lang4.html#E2:32_1_2_1"><i><font color="Green" title="E31">A9</font></i></a></i>
;<br/>
<a NAME="E4:32_1_2_1_1"/>
<font color="Maroon" title="c6">t</font> <a href="finseq_1.html#K8" title="FINSEQ_1:func.8">^</a> <span class="p1"><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">&lt;*</a><span class="default"><font color="Maroon" title="c7">n</font></span><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">*&gt;</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="trees_2.html#K1" title="TREES_2:func.1">succ</a> <font color="Maroon" title="c6">t</font>
 
<b>by </b><i><a class="txt" href="qc_lang4.html#E1:32_1_2_1_1"><i><font color="Green" title="E34">A12</font></i></a></i>;<br/>
<a NAME="E5:32_1_2_1_1"/><b>then </b>
<font color="Maroon" title="c7">n</font> <a href="xxreal_0.html#NR3" title="XXREAL_0:NR.3">&lt;</a>  <a href="card_1.html#K5" title="CARD_1:func.5">card</a> <span class="p1">(<span class="default"><a href="trees_2.html#K1" title="TREES_2:func.1">succ</a> <font color="Maroon" title="c6">t</font></span>)</span>
 
<b>by </b><i><a class="ref" href="trees_9.html#T7" title="TREES_9:th.7">TREES_9:7</a></i>;<br/>
<a NAME="E6:32_1_2_1_1"/><b>then </b>
<font color="Maroon" title="c7">n</font> <a href="xxreal_0.html#NR3" title="XXREAL_0:NR.3">&lt;</a>  <a href="finseq_1.html#K3" title="FINSEQ_1:func.3">len</a> <span class="p1">(<span class="default"><font color="Maroon" title="c6">t</font> <a href="trees_9.html#K1" title="TREES_9:func.1">succ</a> </span>)</span>
 
<b>by </b><i><a class="ref" href="trees_9.html#D5" title="TREES_9:def.5">TREES_9:def 5</a></i>;<br/>
<a NAME="E7:32_1_2_1_1"/><b>then </b>
<font color="Maroon" title="c7">n</font> <a href="xxreal_0.html#NR3" title="XXREAL_0:NR.3">&lt;</a>  <a href="finseq_1.html#K3" title="FINSEQ_1:func.3">len</a> <span class="p1">(<span class="default"><a href="trees_9.html#K2" title="TREES_9:func.2">succ</a> <font color="Maroon" title="c4">t1</font>,<font color="Maroon" title="c6">t</font></span>)</span>
 
<b>by </b><i><a class="ref" href="trees_9.html#T29" title="TREES_9:th.29">TREES_9:29</a></i>;<br/>
<a NAME="E8:32_1_2_1_1"/><b>then </b>
<font color="Maroon" title="c7">n</font> <a href="xxreal_0.html#NR3" title="XXREAL_0:NR.3">&lt;</a>  <a href="finseq_1.html#K3" title="FINSEQ_1:func.3">len</a> <span class="p1">(<span class="default"><font color="Maroon" title="c8">t'</font> <a href="trees_9.html#K1" title="TREES_9:func.1">succ</a> </span>)</span>
 
<b>by </b><i><a class="txt" href="qc_lang4.html#E3:32_1_2_1_1"><i><font color="Green" title="E35">A13</font></i></a>, <a class="ref" href="trees_9.html#T29" title="TREES_9:th.29">TREES_9:29</a></i>;<br/>
<a NAME="E9:32_1_2_1_1"/><b>then </b>
<font color="Maroon" title="c7">n</font> <a href="xxreal_0.html#NR3" title="XXREAL_0:NR.3">&lt;</a>  <a href="card_1.html#K5" title="CARD_1:func.5">card</a> <span class="p1">(<span class="default"><a href="trees_2.html#K1" title="TREES_2:func.1">succ</a> <font color="Maroon" title="c8">t'</font></span>)</span>
 
<b>by </b><i><a class="ref" href="trees_9.html#D5" title="TREES_9:def.5">TREES_9:def 5</a></i>;<br/>
<a NAME="E10:32_1_2_1_1"/><b>then </b><i><font color="Green" title="E36">A14</font></i>: 
<font color="Maroon" title="c8">t'</font> <a href="finseq_1.html#K8" title="FINSEQ_1:func.8">^</a> <span class="p1"><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">&lt;*</a><span class="default"><font color="Maroon" title="c7">n</font></span><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">*&gt;</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="trees_2.html#K1" title="TREES_2:func.1">succ</a> <font color="Maroon" title="c8">t'</font>
 
<b>by </b><i><a class="ref" href="trees_9.html#T7" title="TREES_9:th.7">TREES_9:7</a></i>;<br/>
<b>hence </b><a NAME="E11:32_1_2_1_1"/>
<font color="Maroon" title="c6">t</font> <a href="finseq_1.html#K8" title="FINSEQ_1:func.8">^</a> <span class="p1"><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">&lt;*</a><span class="default"><font color="Maroon" title="c7">n</font></span><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">*&gt;</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c5">t2</font>
 ;<br/>

<b>thus </b><font color="Maroon" title="c4">t1</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c6">t</font> <a href="finseq_1.html#K8" title="FINSEQ_1:func.8">^</a> <span class="p2"><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">&lt;*</a><span class="default"><font color="Maroon" title="c7">n</font></span><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">*&gt;</a></span></span>)</span> = 
<span class="p1">(<span class="default"><a href="trees_9.html#K2" title="TREES_9:func.2">succ</a> <font color="Maroon" title="c5">t2</font>,<font color="Maroon" title="c8">t'</font></span>)</span> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c7">n</font> <a href="nat_1.html#K2" title="NAT_1:func.2">+</a> 1</span>)</span>
<b>by </b><i><a class="txt" href="qc_lang4.html#E1:32_1_2_1_1"><i><font color="Green" title="E34">A12</font></i></a>, <a class="txt" href="qc_lang4.html#E3:32_1_2_1_1"><i><font color="Green" title="E35">A13</font></i></a>, <a class="ref" href="qc_lang4.html#T13" target="_self" title="QC_LANG4:th.13">Th13</a></i>
<br/>.= 
<font color="Maroon" title="c5">t2</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c6">t</font> <a href="finseq_1.html#K8" title="FINSEQ_1:func.8">^</a> <span class="p2"><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">&lt;*</a><span class="default"><font color="Maroon" title="c7">n</font></span><a href="finseq_1.html#K12" title="FINSEQ_1:func.12">*&gt;</a></span></span>)</span>
<b>by </b><i><a class="txt" href="qc_lang4.html#E10:32_1_2_1_1"><i><font color="Green" title="E36">A14</font></i></a>, <a class="ref" href="qc_lang4.html#T13" target="_self" title="QC_LANG4:th.13">Th13</a></i>
;<br/>


</div><b>end;</b></div>
<a NAME="E5:32_1_2_1"/><i><font color="Green" title="E34">A15</font></i>: 
for <font color="Olive" title="b1">t</font> being   <a href="trees_1.html#M1" title="TREES_1:mode.1">Element</a> of  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c4">t1</font> holds  <font color="Maroon">S<sub>1</sub></font>[<font color="Olive" title="b1">t</font>]
 
<b>from </b><i><a class="ref" href="trees_2.html#S1" title="TREES_2:sch.1">TREES_2:sch 1</a>(<a class="txt" href="qc_lang4.html#E3:32_1_2_1"><i><font color="Green" title="E32">A10</font></i></a>, <a class="txt" href="qc_lang4.html#E4:32_1_2_1"><i><font color="Green" title="E33">A11</font></i></a>);<br/></i>
<a NAME="E6:32_1_2_1"/><b>then </b>
for <font color="Olive" title="b1">t</font> being   <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a>   st <font color="Olive" title="b1">t</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c4">t1</font> holds <br/><font color="Olive" title="b1">t</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c5">t2</font>
 
;<br/>
<a NAME="E7:32_1_2_1"/><b>then </b><i><font color="Green" title="E35">A16</font></i>: 
 <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c4">t1</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a>  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c5">t2</font>
 
<b>by </b><i><a class="ref" href="tarski.html#D3" title="TARSKI:def.3">TARSKI:def 3</a></i>;<br/>
<a NAME="E8:32_1_2_1"/>
for <font color="Olive" title="b1">x</font> being   <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a>   st <font color="Olive" title="b1">x</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="relat_1.html#NK2" title="RELAT_1:NK.2">dom</a> <font color="Maroon" title="c4">t1</font> holds <br/><font color="Maroon" title="c4">t1</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <font color="Olive" title="b1">x</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c5">t2</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <font color="Olive" title="b1">x</font>
 
<b>by </b><i><a class="txt" href="qc_lang4.html#E5:32_1_2_1"><i><font color="Green" title="E34">A15</font></i></a></i>;<br/>
<b>hence </b><a NAME="E9:32_1_2_1"/>
<font color="Maroon" title="c4">t1</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c5">t2</font>
 <b>by </b><i><a class="txt" href="qc_lang4.html#E7:32_1_2_1"><i><font color="Green" title="E35">A16</font></i></a>, <a class="ref" href="grfunc_1.html#T8" title="GRFUNC_1:th.8">GRFUNC_1:8</a></i>;<br/>


</div><b>end;</b></div>
<a NAME="E4:32_1_2"/><b>then </b>
( <font color="Maroon" title="c2">t1</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c3">t2</font> &amp; <font color="Maroon" title="c3">t2</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c2">t1</font> )
 
<b>by </b><i><a class="txt" href="qc_lang4.html#E1:32_1_2"><i><font color="Green" title="E28">A6</font></i></a>, <a class="txt" href="qc_lang4.html#E2:32_1_2"><i><font color="Green" title="E29">A7</font></i></a></i>;<br/>
<b>hence </b><a NAME="E5:32_1_2"/>
<font color="Maroon" title="c2">t1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c3">t2</font>
 <b>by </b><i><a class="ref" href="xboole_0.html#D10" title="XBOOLE_0:def.10">XBOOLE_0:def 10</a></i>;<br/>


</div>
