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<span class="kw">let </span><font color="Maroon" title="c3">O1</font>, <font color="Maroon" title="c4">O2</font> be   <a href="mmlquery.html#NM2" title="MMLQUERY:NM.2">Operation</a> of <font color="Maroon" title="c1">X</font>; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> ( (  for <font color="Olive" title="b1">L</font> being   <a href="mmlquery.html#NM1" title="MMLQUERY:NM.1">List</a> of <font color="Maroon" title="c1">X</font> holds  <font color="Olive" title="b1">L</font> <a href="mmlquery.html#K2" title="MMLQUERY:func.2">|</a> <font color="Maroon" title="c3">O1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="tarski.html#K3" title="TARSKI:func.3">union</a> <span class="p1"> { <span class="default"> <span class="p2">(<span class="default"><a href="funcop_1.html#K15" title="FUNCOP_1:func.15">IFEQ</a> (<span class="p3">(<span class="default"><font color="Olive" title="b2">x</font> <a href="mmlquery.html#K1" title="MMLQUERY:func.1">.</a> <font color="Maroon" title="c2">O</font></span>)</span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>,<span class="p3"><a href="tarski.html#K1" title="TARSKI:func.1">{</a><span class="default"><font color="Olive" title="b2">x</font></span><a href="tarski.html#K1" title="TARSKI:func.1">}</a></span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>)</span>)</span> where <font color="Olive" title="b2">x</font> is    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of <font color="Maroon" title="c1">X</font> : <font color="Olive" title="b2">x</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a> <font color="Olive" title="b1">L</font> </span> } </span>  ) &amp; (  for <font color="Olive" title="b1">L</font> being   <a href="mmlquery.html#NM1" title="MMLQUERY:NM.1">List</a> of <font color="Maroon" title="c1">X</font> holds  <font color="Olive" title="b1">L</font> <a href="mmlquery.html#K2" title="MMLQUERY:func.2">|</a> <font color="Maroon" title="c4">O2</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="tarski.html#K3" title="TARSKI:func.3">union</a> <span class="p1"> { <span class="default"> <span class="p2">(<span class="default"><a href="funcop_1.html#K15" title="FUNCOP_1:func.15">IFEQ</a> (<span class="p3">(<span class="default"><font color="Olive" title="b2">x</font> <a href="mmlquery.html#K1" title="MMLQUERY:func.1">.</a> <font color="Maroon" title="c2">O</font></span>)</span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>,<span class="p3"><a href="tarski.html#K1" title="TARSKI:func.1">{</a><span class="default"><font color="Olive" title="b2">x</font></span><a href="tarski.html#K1" title="TARSKI:func.1">}</a></span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>)</span>)</span> where <font color="Olive" title="b2">x</font> is    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of <font color="Maroon" title="c1">X</font> : <font color="Olive" title="b2">x</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a> <font color="Olive" title="b1">L</font> </span> } </span>  ) implies <font color="Maroon" title="c3">O1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c4">O2</font> )</span><br/>

<span class="kw">assume </span><span class="kw">that </span><br/><a NAME="E1:39_1_2"/><span class="lab"><font color="Green" title="E12">A8</font></span>: 
 for <font color="Olive" title="b1">L</font> being   <a href="mmlquery.html#NM1" title="MMLQUERY:NM.1">List</a> of <font color="Maroon" title="c1">X</font> holds  <font color="Olive" title="b1">L</font> <a href="mmlquery.html#K2" title="MMLQUERY:func.2">|</a> <font color="Maroon" title="c3">O1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="tarski.html#K3" title="TARSKI:func.3">union</a> <span class="p1"> { <span class="default"> <span class="p2">(<span class="default"><a href="funcop_1.html#K15" title="FUNCOP_1:func.15">IFEQ</a> (<span class="p3">(<span class="default"><font color="Olive" title="b2">x</font> <a href="mmlquery.html#K1" title="MMLQUERY:func.1">.</a> <font color="Maroon" title="c2">O</font></span>)</span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>,<span class="p3"><a href="tarski.html#K1" title="TARSKI:func.1">{</a><span class="default"><font color="Olive" title="b2">x</font></span><a href="tarski.html#K1" title="TARSKI:func.1">}</a></span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>)</span>)</span> where <font color="Olive" title="b2">x</font> is    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of <font color="Maroon" title="c1">X</font> : <font color="Olive" title="b2">x</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a> <font color="Olive" title="b1">L</font> </span> } </span> 
 <span class="kw">and </span><br/><a NAME="E2:39_1_2"/><span class="lab"><font color="Green" title="E13">A9</font></span>: 
 for <font color="Olive" title="b1">L</font> being   <a href="mmlquery.html#NM1" title="MMLQUERY:NM.1">List</a> of <font color="Maroon" title="c1">X</font> holds  <font color="Olive" title="b1">L</font> <a href="mmlquery.html#K2" title="MMLQUERY:func.2">|</a> <font color="Maroon" title="c4">O2</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="tarski.html#K3" title="TARSKI:func.3">union</a> <span class="p1"> { <span class="default"> <span class="p2">(<span class="default"><a href="funcop_1.html#K15" title="FUNCOP_1:func.15">IFEQ</a> (<span class="p3">(<span class="default"><font color="Olive" title="b2">x</font> <a href="mmlquery.html#K1" title="MMLQUERY:func.1">.</a> <font color="Maroon" title="c2">O</font></span>)</span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>,<span class="p3"><a href="tarski.html#K1" title="TARSKI:func.1">{</a><span class="default"><font color="Olive" title="b2">x</font></span><a href="tarski.html#K1" title="TARSKI:func.1">}</a></span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>)</span>)</span> where <font color="Olive" title="b2">x</font> is    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of <font color="Maroon" title="c1">X</font> : <font color="Olive" title="b2">x</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a> <font color="Olive" title="b1">L</font> </span> } </span> 
 ; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> <font color="Maroon" title="c3">O1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c4">O2</font></span><br/>

<div><a class="txt" onmouseover="tooltip.show('hs2',this)" onmouseout="tooltip.hide()" onclick="hs2(this)" href="javascript:()" title="39_1_2_1"><span class="kw">now </span> <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide">  for <font color="Olive" title="b1">L</font> being   <a href="mmlquery.html#NM1" title="MMLQUERY:NM.1">List</a> of <font color="Maroon" title="c1">X</font> holds  <font color="Olive" title="b1">L</font> <a href="mmlquery.html#K2" title="MMLQUERY:func.2">|</a> <font color="Maroon" title="c3">O1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b1">L</font> <a href="mmlquery.html#K2" title="MMLQUERY:func.2">|</a> <font color="Maroon" title="c4">O2</font></span></a><div class="add"><span class="kw">let </span><font color="Maroon" title="c5">L</font> be   <a href="mmlquery.html#NM1" title="MMLQUERY:NM.1">List</a> of <font color="Maroon" title="c1">X</font>; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> <font color="Maroon" title="c5">L</font> <a href="mmlquery.html#K2" title="MMLQUERY:func.2">|</a> <font color="Maroon" title="c3">O1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c5">L</font> <a href="mmlquery.html#K2" title="MMLQUERY:func.2">|</a> <font color="Maroon" title="c4">O2</font></span><br/><span class="kw">thus </span><font color="Maroon" title="c5">L</font> <a href="mmlquery.html#K2" title="MMLQUERY:func.2">|</a> <font color="Maroon" title="c3">O1</font> = 
 <a href="tarski.html#K3" title="TARSKI:func.3">union</a> <span class="p1"> { <span class="default"> <span class="p2">(<span class="default"><a href="funcop_1.html#K15" title="FUNCOP_1:func.15">IFEQ</a> (<span class="p3">(<span class="default"><font color="Olive" title="b1">x</font> <a href="mmlquery.html#K1" title="MMLQUERY:func.1">.</a> <font color="Maroon" title="c2">O</font></span>)</span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>,<span class="p3"><a href="tarski.html#K1" title="TARSKI:func.1">{</a><span class="default"><font color="Olive" title="b1">x</font></span><a href="tarski.html#K1" title="TARSKI:func.1">}</a></span>,<a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>)</span>)</span> where <font color="Olive" title="b1">x</font> is    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of <font color="Maroon" title="c1">X</font> : <font color="Olive" title="b1">x</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a> <font color="Maroon" title="c5">L</font> </span> } </span> 
<span class="kw">by</span> <span class="lab"><a class="txt" href="#E1:39_1_2"><span class="lab"><font color="Green" title="E12">A8</font></span></a></span>
<br/>.= 
<font color="Maroon" title="c5">L</font> <a href="mmlquery.html#K2" title="MMLQUERY:func.2">|</a> <font color="Maroon" title="c4">O2</font>
<span class="kw">by</span> <span class="lab"><a class="txt" href="#E2:39_1_2"><span class="lab"><font color="Green" title="E13">A9</font></span></a></span>
; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> verum</span><br/></div><span class="kw">end;</span></div>
<span class="kw">hence </span><a NAME="E4:39_1_2"/>
<font color="Maroon" title="c3">O1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c4">O2</font>
 <span class="kw">by</span> <span class="lab"><a class="ref" href="mmlquery.html#T30" target="_self" onmouseover="rs('mmlquery/T30')" onmouseout="rh()">Th30</a></span>; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> verum</span><br/>


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