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<div class="add">

<b>defpred </b><font color="Maroon">S<sub>1</sub></font>[   <a href="subset_1.html#M1">Element</a> of  <a href="card_3.html#K4">product</a> <font color="Maroon">a</font>,   <a href="subset_1.html#M1">Element</a> of  <a href="card_3.html#K4">product</a> <font color="Maroon">a</font>,   <a href="subset_1.html#M1">Element</a> of  <a href="card_3.html#K4">product</a> <font color="Maroon">a</font>] <b>means </b>for <font color="Olive">i</font> being   <a href="subset_1.html#M2">Element</a> of  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font> holds  <font color="Maroon">a<sub>3</sub></font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">i</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><font color="Maroon">b</font> <a href="prvect_1.html#K10" target="_self">.</a> <font color="Olive">i</font></span>)</span> <a href="binop_1.html#K2">.</a> <span class="p1">(<span class="default"><font color="Maroon">a<sub>1</sub></font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">i</font></span>)</span>,<span class="p1">(<span class="default"><font color="Maroon">a<sub>2</sub></font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">i</font></span>)</span>;<br/>
<a NAME="E1:46_1_1"/><i><font color="Green">E22</font></i>: 
for <font color="Olive">f</font>, <font color="Olive">g</font> being   <a href="subset_1.html#M1">Element</a> of  <a href="card_3.html#K4">product</a> <font color="Maroon">a</font>  ex <font color="Olive">z</font> being   <a href="subset_1.html#M1">Element</a> of  <a href="card_3.html#K4">product</a> <font color="Maroon">a</font> st <font color="Maroon">S<sub>1</sub></font>[<font color="Olive">f</font>,<font color="Olive">g</font>,<font color="Olive">z</font>]
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="46_1_1_1"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">f</font> be    <a href="subset_1.html#M1">Element</a> of  <a href="card_3.html#K4">product</a> <font color="Maroon">a</font>, <font color="Maroon">g</font> be    <a href="subset_1.html#M1">Element</a> of  <a href="card_3.html#K4">product</a> <font color="Maroon">a</font>;<br/>

<b>defpred </b><font color="Maroon">S<sub>2</sub></font>[   <a href="hidden.html#M1">set</a> ,   <a href="hidden.html#M1">set</a> ] <b>means </b> ex <font color="Olive">i</font> being   <a href="subset_1.html#M2">Element</a> of  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font> st <br/>( <font color="Maroon">a<sub>1</sub></font> <a href="hidden.html#R1">=</a> <font color="Olive">i</font> &amp; <font color="Maroon">a<sub>2</sub></font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><font color="Maroon">b</font> <a href="prvect_1.html#K10" target="_self">.</a> <font color="Olive">i</font></span>)</span> <a href="binop_1.html#K2">.</a> <span class="p1">(<span class="default"><font color="Maroon">f</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">i</font></span>)</span>,<span class="p1">(<span class="default"><font color="Maroon">g</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">i</font></span>)</span> );<br/>
<a NAME="E1:46_1_1_1"/><i><font color="Green">E25</font></i>: 
for <font color="Olive">x</font>, <font color="Olive">z1</font>, <font color="Olive">z2</font> being   <a href="hidden.html#M1">set</a>   st <font color="Olive">x</font> <a href="hidden.html#R2">in</a>  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font> &amp; <font color="Maroon">S<sub>2</sub></font>[<font color="Olive">x</font>,<font color="Olive">z1</font>] &amp; <font color="Maroon">S<sub>2</sub></font>[<font color="Olive">x</font>,<font color="Olive">z2</font>] holds <br/><font color="Olive">z1</font> <a href="hidden.html#R1">=</a> <font color="Olive">z2</font>
 
;<br/>
<a NAME="E2:46_1_1_1"/><i><font color="Green">E26</font></i>: 
for <font color="Olive">x</font> being   <a href="hidden.html#M1">set</a>   st <font color="Olive">x</font> <a href="hidden.html#R2">in</a>  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font> holds <br/> ex <font color="Olive">z</font> being   <a href="hidden.html#M1">set</a>  st <font color="Maroon">S<sub>2</sub></font>[<font color="Olive">x</font>,<font color="Olive">z</font>]
 
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="46_1_1_1_1"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">x</font> be    <a href="hidden.html#M1">set</a> ;<br/>

<b>assume </b><a NAME="E1:46_1_1_1_1"/>
<font color="Maroon">x</font> <a href="hidden.html#R2">in</a>  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font>
 ;<br/>

<b>then reconsider </b><font color="Maroon">i</font> = <font color="Maroon">x</font> as    <a href="subset_1.html#M2">Element</a> of  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font> ;<br/>
<b>take </b>
<span class="p1">(<span class="default"><font color="Maroon">b</font> <a href="prvect_1.html#K10" target="_self">.</a> <font color="Maroon">i</font></span>)</span> <a href="binop_1.html#K2">.</a> <span class="p1">(<span class="default"><font color="Maroon">f</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Maroon">i</font></span>)</span>,<span class="p1">(<span class="default"><font color="Maroon">g</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Maroon">i</font></span>)</span>
;<br/>

<b>thus </b><a NAME="E3:46_1_1_1_1"/>
<font color="Maroon">S<sub>2</sub></font>[<font color="Maroon">x</font>,<span class="p1">(<span class="default"><font color="Maroon">b</font> <a href="prvect_1.html#K10" target="_self">.</a> <font color="Maroon">i</font></span>)</span> <a href="binop_1.html#K2">.</a> <span class="p1">(<span class="default"><font color="Maroon">f</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Maroon">i</font></span>)</span>,<span class="p1">(<span class="default"><font color="Maroon">g</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Maroon">i</font></span>)</span>]
 ;<br/>


</div><b>end;</b></div>
<b>consider </b><font color="Maroon">z</font> being   <a href="funct_1.html#NM1">Function</a><b> such that </b><br/><a NAME="E4:46_1_1_1"/><i><font color="Green">E27</font></i>: 
(  <a href="relat_1.html#K1">dom</a> <font color="Maroon">z</font> <a href="hidden.html#R1">=</a>  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font> &amp; ( for <font color="Olive">x</font> being   <a href="hidden.html#M1">set</a>   st <font color="Olive">x</font> <a href="hidden.html#R2">in</a>  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font> holds <br/><font color="Maroon">S<sub>2</sub></font>[<font color="Olive">x</font>,<font color="Maroon">z</font> <a href="funct_1.html#K1">.</a> <font color="Olive">x</font>] ) )
 <b>from </b><i><a class="ref" href="funct_1.html#S2">FUNCT_1:sch 2</a>(<a class="txt" href="prvect_1.html#E4:46_1_1_1"><i><font color="Green">E27</font></i></a>, );<br/></i>
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="46_1_1_1_2"><b>now </b></a><div class="add"><b>let </b><font color="Maroon">x</font> be    <a href="hidden.html#M1">set</a> ;<br/><b>assume </b><a NAME="E1:46_1_1_1_2"/>
<font color="Maroon">x</font> <a href="hidden.html#R2">in</a>  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font>
 ;<br/><a NAME="E2:46_1_1_1_2"/><b>then </b>
 ex <font color="Olive">i</font> being   <a href="subset_1.html#M2">Element</a> of  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font> st <br/>( <font color="Maroon">x</font> <a href="hidden.html#R1">=</a> <font color="Olive">i</font> &amp; <font color="Maroon">z</font> <a href="funct_1.html#K1">.</a> <font color="Maroon">x</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><font color="Maroon">b</font> <a href="prvect_1.html#K10" target="_self">.</a> <font color="Olive">i</font></span>)</span> <a href="binop_1.html#K2">.</a> <span class="p1">(<span class="default"><font color="Maroon">f</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">i</font></span>)</span>,<span class="p1">(<span class="default"><font color="Maroon">g</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">i</font></span>)</span> )
 <b>by </b><i/>;<br/><b>hence </b><a NAME="E3:46_1_1_1_2"/>
<font color="Maroon">z</font> <a href="funct_1.html#K1">.</a> <font color="Maroon">x</font> <a href="hidden.html#R2">in</a> <font color="Maroon">a</font> <a href="funct_1.html#K1">.</a> <font color="Maroon">x</font>
 ;<br/></div><b>end;</b></div>
<b>then reconsider </b><font color="Maroon">z'</font> = <font color="Maroon">z</font> as    <a href="subset_1.html#M1">Element</a> of  <a href="card_3.html#K4">product</a> <font color="Maroon">a</font> <b>by </b><i>, <a class="ref" href="card_3.html#T18">CARD_3:18</a></i>;<br/>
<b>take </b>
<font color="Maroon">z'</font>
;<br/>

<b>let </b><font color="Maroon">i</font> be    <a href="subset_1.html#M2">Element</a> of  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font>;<br/>

<a NAME="E7:46_1_1_1"/>
 ex <font color="Olive">j</font> being   <a href="subset_1.html#M2">Element</a> of  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font> st <br/>( <font color="Olive">j</font> <a href="hidden.html#R1">=</a> <font color="Maroon">i</font> &amp; <font color="Maroon">z</font> <a href="funct_1.html#K1">.</a> <font color="Maroon">i</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><font color="Maroon">b</font> <a href="prvect_1.html#K10" target="_self">.</a> <font color="Olive">j</font></span>)</span> <a href="binop_1.html#K2">.</a> <span class="p1">(<span class="default"><font color="Maroon">f</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">j</font></span>)</span>,<span class="p1">(<span class="default"><font color="Maroon">g</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">j</font></span>)</span> )
 
<b>by </b><i/>;<br/>
<b>hence </b><a NAME="E8:46_1_1_1"/>
<font color="Maroon">z'</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Maroon">i</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><font color="Maroon">b</font> <a href="prvect_1.html#K10" target="_self">.</a> <font color="Maroon">i</font></span>)</span> <a href="binop_1.html#K2">.</a> <span class="p1">(<span class="default"><font color="Maroon">f</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Maroon">i</font></span>)</span>,<span class="p1">(<span class="default"><font color="Maroon">g</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Maroon">i</font></span>)</span>
 ;<br/>


</div><b>end;</b></div>
<b>consider </b><font color="Maroon">d</font> being   <a href="binop_1.html#NM2">BinOp</a> of  <a href="card_3.html#K4">product</a> <font color="Maroon">a</font><b> such that </b><br/><a NAME="E3:46_1_1"/><i><font color="Green">E55</font></i>: 
for <font color="Olive">f</font>, <font color="Olive">g</font> being   <a href="subset_1.html#M1">Element</a> of  <a href="card_3.html#K4">product</a> <font color="Maroon">a</font> holds  <font color="Maroon">S<sub>1</sub></font>[<font color="Olive">f</font>,<font color="Olive">g</font>,<font color="Maroon">d</font> <a href="prvect_1.html#K13" target="_self">.</a> <font color="Olive">f</font>,<font color="Olive">g</font>]
 <b>from </b><i><a class="ref" href="binop_1.html#S3">BINOP_1:sch 3</a>();<br/></i>
<b>take </b>
<font color="Maroon">d</font>
;<br/>

<b>thus </b><a NAME="E4:46_1_1"/>
for <font color="Olive">f</font>, <font color="Olive">g</font> being   <a href="subset_1.html#M1">Element</a> of  <a href="card_3.html#K4">product</a> <font color="Maroon">a</font><br/> for <font color="Olive">i</font> being   <a href="subset_1.html#M2">Element</a> of  <a href="finseq_1.html#K4">dom</a> <font color="Maroon">a</font> holds  <span class="p1">(<span class="default"><font color="Maroon">d</font> <a href="prvect_1.html#K13" target="_self">.</a> <font color="Olive">f</font>,<font color="Olive">g</font></span>)</span> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">i</font> <a href="hidden.html#R1">=</a> <span class="p1">(<span class="default"><font color="Maroon">b</font> <a href="prvect_1.html#K10" target="_self">.</a> <font color="Olive">i</font></span>)</span> <a href="binop_1.html#K2">.</a> <span class="p1">(<span class="default"><font color="Olive">f</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">i</font></span>)</span>,<span class="p1">(<span class="default"><font color="Olive">g</font> <a href="prvect_1.html#K9" target="_self">.</a> <font color="Olive">i</font></span>)</span>
 <b>by </b><i/>;<br/>


</div>
