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<b>let </b><font color="Maroon" title="c1">a</font> be    <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a> ; <i><font color="Red">:: according to </font></i><a class="ref" href="tarski.html#D3" title="TARSKI:def.3">TARSKI:def 3</a><br/>

<b>assume </b><a NAME="E1:49"/>
<font color="Maroon" title="c1">a</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a> <span class="p1"><a href="zfmisc_1.html#K2" title="ZFMISC_1:func.2">[:</a><span class="default"><a href="qc_lang1.html#K8" title="QC_LANG1:func.8">QC-WFF</a> ,<a href="substut1.html#K1" title="SUBSTUT1:func.1">vSUB</a> </span><a href="zfmisc_1.html#K2" title="ZFMISC_1:func.2">:]</a></span>
 ;<br/>

<b>then consider </b><font color="Maroon" title="c2">b</font>, <font color="Maroon" title="c3">c</font> being    <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a> <b> such that </b><br/><a NAME="E3:49"/><i><font color="Green" title="E36">A1</font></i>: 
( <font color="Maroon" title="c2">b</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="qc_lang1.html#K8" title="QC_LANG1:func.8">QC-WFF</a>  &amp; <font color="Maroon" title="c3">c</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="substut1.html#K1" title="SUBSTUT1:func.1">vSUB</a>  &amp; <font color="Maroon" title="c1">a</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c2">b</font>,<font color="Maroon" title="c3">c</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> )
 <b>by </b><i><a class="ref" href="zfmisc_1.html#D2" title="ZFMISC_1:def.2">ZFMISC_1:def 2</a></i>;<br/>
<b>reconsider </b><font color="Maroon" title="c4">p</font> = <font color="Maroon" title="c2">b</font> as    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of  <a href="qc_lang1.html#K8" title="QC_LANG1:func.8">QC-WFF</a>  <b>by </b><i><a class="txt" href="sublemma.html#E3:49"><i><font color="Green" title="E36">A1</font></i></a></i>;<br/>
<b>reconsider </b><font color="Maroon" title="c5">Sub</font> = <font color="Maroon" title="c3">c</font> as   <a href="substut1.html#NM1" title="SUBSTUT1:NM.1">CQC_Substitution</a> <b>by </b><i><a class="txt" href="sublemma.html#E3:49"><i><font color="Green" title="E36">A1</font></i></a></i>;<br/>
<div><i><font color="Green" title="E37">A2</font></i>: <a class="txt" onclick="hs2(this)" href="javascript:()" title="49_1"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:49_1"/><i><font color="Green" title="E38">A3</font></i>: 
<font color="Maroon" title="c4">p</font> is <a href="qc_lang1.html#V5" title="QC_LANG1:attr.5">universal</a>
 ;<br/><b>set </b><font color="Maroon" title="c6">b</font> =  <a href="substut1.html#K14" title="SUBSTUT1:func.14">ExpandSub</a> <span class="p1">(<span class="default"><a href="qc_lang1.html#K20" title="QC_LANG1:func.20">bound_in</a> <font color="Maroon" title="c4">p</font></span>)</span>,<span class="p1">(<span class="default"><a href="qc_lang1.html#K21" title="QC_LANG1:func.21">the_scope_of</a> <font color="Maroon" title="c4">p</font></span>)</span>,<span class="p1">(<span class="default"><a href="substut1.html#K7" title="SUBSTUT1:func.7">RestrictSub</a> <span class="p2">(<span class="default"><a href="qc_lang1.html#K20" title="QC_LANG1:func.20">bound_in</a> <font color="Maroon" title="c4">p</font></span>)</span>,<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">Sub</font></span>)</span>;<br/><a NAME="E2:49_1"/><i><font color="Green" title="E39">A4</font></i>: 
<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">Sub</font> <a href="substut1.html#R1" title="SUBSTUT1:pred.1">PQSub</a>  <a href="substut1.html#K14" title="SUBSTUT1:func.14">ExpandSub</a> <span class="p1">(<span class="default"><a href="qc_lang1.html#K20" title="QC_LANG1:func.20">bound_in</a> <font color="Maroon" title="c4">p</font></span>)</span>,<span class="p1">(<span class="default"><a href="qc_lang1.html#K21" title="QC_LANG1:func.21">the_scope_of</a> <font color="Maroon" title="c4">p</font></span>)</span>,<span class="p1">(<span class="default"><a href="substut1.html#K7" title="SUBSTUT1:func.7">RestrictSub</a> <span class="p2">(<span class="default"><a href="qc_lang1.html#K20" title="QC_LANG1:func.20">bound_in</a> <font color="Maroon" title="c4">p</font></span>)</span>,<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">Sub</font></span>)</span>
 <b>by </b><i><a class="txt" href="sublemma.html#E1:49_1"><i><font color="Green" title="E38">A3</font></i></a>, <a class="ref" href="substut1.html#D14" title="SUBSTUT1:def.14">SUBSTUT1:def 14</a></i>;<br/><b>set </b><font color="Maroon" title="c7">a</font> = <span class="p1"><a href="domain_1.html#K1" title="DOMAIN_1:func.1">[</a><span class="default"><span class="p2"><a href="domain_1.html#K1" title="DOMAIN_1:func.1">[</a><span class="default"><font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">Sub</font></span><a href="domain_1.html#K1" title="DOMAIN_1:func.1">]</a></span>,<span class="p2">(<span class="default"><a href="substut1.html#K14" title="SUBSTUT1:func.14">ExpandSub</a> <span class="p3">(<span class="default"><a href="qc_lang1.html#K20" title="QC_LANG1:func.20">bound_in</a> <font color="Maroon" title="c4">p</font></span>)</span>,<span class="p3">(<span class="default"><a href="qc_lang1.html#K21" title="QC_LANG1:func.21">the_scope_of</a> <font color="Maroon" title="c4">p</font></span>)</span>,<span class="p3">(<span class="default"><a href="substut1.html#K7" title="SUBSTUT1:func.7">RestrictSub</a> <span class="p4">(<span class="default"><a href="qc_lang1.html#K20" title="QC_LANG1:func.20">bound_in</a> <font color="Maroon" title="c4">p</font></span>)</span>,<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">Sub</font></span>)</span></span>)</span></span><a href="domain_1.html#K1" title="DOMAIN_1:func.1">]</a></span>;<br/><a NAME="E3:49_1"/>
<span class="p1"><a href="domain_1.html#K1" title="DOMAIN_1:func.1">[</a><span class="default"><span class="p2"><a href="domain_1.html#K1" title="DOMAIN_1:func.1">[</a><span class="default"><font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">Sub</font></span><a href="domain_1.html#K1" title="DOMAIN_1:func.1">]</a></span>,<span class="p2">(<span class="default"><a href="substut1.html#K14" title="SUBSTUT1:func.14">ExpandSub</a> <span class="p3">(<span class="default"><a href="qc_lang1.html#K20" title="QC_LANG1:func.20">bound_in</a> <font color="Maroon" title="c4">p</font></span>)</span>,<span class="p3">(<span class="default"><a href="qc_lang1.html#K21" title="QC_LANG1:func.21">the_scope_of</a> <font color="Maroon" title="c4">p</font></span>)</span>,<span class="p3">(<span class="default"><a href="substut1.html#K7" title="SUBSTUT1:func.7">RestrictSub</a> <span class="p4">(<span class="default"><a href="qc_lang1.html#K20" title="QC_LANG1:func.20">bound_in</a> <font color="Maroon" title="c4">p</font></span>)</span>,<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">Sub</font></span>)</span></span>)</span></span><a href="domain_1.html#K1" title="DOMAIN_1:func.1">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="substut1.html#K15" title="SUBSTUT1:func.15">QSub</a> 
 <b>by </b><i><a class="txt" href="sublemma.html#E2:49_1"><i><font color="Green" title="E39">A4</font></i></a>, <a class="ref" href="substut1.html#D15" title="SUBSTUT1:def.15">SUBSTUT1:def 15</a></i>;<br/><b>hence </b><a NAME="E4:49_1"/>
<font color="Maroon" title="c1">a</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <a href="substut1.html#K15" title="SUBSTUT1:func.15">QSub</a> 
 <b>by </b><i><a class="txt" href="sublemma.html#E3:49"><i><font color="Green" title="E36">A1</font></i></a>, <a class="ref" href="funct_1.html#T8" title="FUNCT_1:th.8">FUNCT_1:8</a></i>;<br/></div><b>end;</b></div>
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="49_2"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:49_2"/><i><font color="Green" title="E38">A5</font></i>: 
not <font color="Maroon" title="c4">p</font> is <a href="qc_lang1.html#V5" title="QC_LANG1:attr.5">universal</a>
 ;<br/><b>set </b><font color="Maroon" title="c6">b</font> =  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> ;<br/><a NAME="E2:49_2"/><i><font color="Green" title="E39">A6</font></i>: 
<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">Sub</font> <a href="substut1.html#R1" title="SUBSTUT1:pred.1">PQSub</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
 <b>by </b><i><a class="txt" href="sublemma.html#E1:49_2"><i><font color="Green" title="E38">A5</font></i></a>, <a class="ref" href="substut1.html#D14" title="SUBSTUT1:def.14">SUBSTUT1:def 14</a></i>;<br/><b>set </b><font color="Maroon" title="c7">a</font> = <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><span class="p2"><a href="domain_1.html#K1" title="DOMAIN_1:func.1">[</a><span class="default"><font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">Sub</font></span><a href="domain_1.html#K1" title="DOMAIN_1:func.1">]</a></span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> </span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span>;<br/><a NAME="E3:49_2"/>
<span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><span class="p2"><a href="domain_1.html#K1" title="DOMAIN_1:func.1">[</a><span class="default"><font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">Sub</font></span><a href="domain_1.html#K1" title="DOMAIN_1:func.1">]</a></span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> </span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="substut1.html#K15" title="SUBSTUT1:func.15">QSub</a> 
 <b>by </b><i><a class="txt" href="sublemma.html#E2:49_2"><i><font color="Green" title="E39">A6</font></i></a>, <a class="ref" href="substut1.html#D15" title="SUBSTUT1:def.15">SUBSTUT1:def 15</a></i>;<br/><b>hence </b><a NAME="E4:49_2"/>
<font color="Maroon" title="c1">a</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <a href="substut1.html#K15" title="SUBSTUT1:func.15">QSub</a> 
 <b>by </b><i><a class="txt" href="sublemma.html#E3:49"><i><font color="Green" title="E36">A1</font></i></a>, <a class="ref" href="funct_1.html#T8" title="FUNCT_1:th.8">FUNCT_1:8</a></i>;<br/></div><b>end;</b></div>
<b>hence </b><a NAME="E8:49"/>
<font color="Maroon" title="c1">a</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="relat_1.html#K1" title="RELAT_1:func.1">dom</a> <a href="substut1.html#K15" title="SUBSTUT1:func.15">QSub</a> 
 <b>by </b><i><a class="txt" href="sublemma.html#E6:49"><i><font color="Green" title="E37">A2</font></i></a></i>;<br/>


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