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<span class="kw">let </span><font color="Maroon" title="c1">R</font> be   <a href="group_1.html#V5" title="GROUP_1:attr.5">commutative</a>  <a href="vectsp_1.html#NM3" title="VECTSP_1:NM.3">Ring</a>; <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">S</font> being   non  <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a>   <a href="c0sp1.html#V3" title="C0SP1:attr.3">multiplicatively-closed</a>  <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <font color="Maroon" title="c1">R</font><br/>  for <font color="Olive" title="b2">z</font> being   <a href="struct_0.html#NM1" title="STRUCT_0:NM.1">Element</a> of <span class="p1">(<span class="default"><font color="Olive" title="b1">S</font> <a href="ringfrac.html#NK17" title="RINGFRAC:NK.17">~</a> <font color="Maroon" title="c1">R</font></span>)</span>  ex <font color="Olive" title="b3">r1</font>, <font color="Olive" title="b4">r2</font> being   <a href="struct_0.html#NM1" title="STRUCT_0:NM.1">Element</a> of <font color="Maroon" title="c1">R</font> st <br/>( <font color="Olive" title="b4">r2</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a> <font color="Olive" title="b1">S</font> &amp; <font color="Olive" title="b2">z</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="eqrel_1.html#K6" title="EQREL_1:func.6">Class</a> (<span class="p1">(<span class="default"><a href="ringfrac.html#K12" title="RINGFRAC:func.12">EqRel</a> <font color="Olive" title="b1">S</font></span>)</span>,<span class="p1"><a href="domain_1.html#K1" title="DOMAIN_1:func.1">[</a><span class="default"><font color="Olive" title="b3">r1</font>,<font color="Olive" title="b4">r2</font></span><a href="domain_1.html#K1" title="DOMAIN_1:func.1">]</a></span>) )</span><br/><span class="kw">let </span><font color="Maroon" title="c2">S</font> be   non  <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a>   <a href="c0sp1.html#V3" title="C0SP1:attr.3">multiplicatively-closed</a>  <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <font color="Maroon" title="c1">R</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">z</font> being   <a href="struct_0.html#NM1" title="STRUCT_0:NM.1">Element</a> of <span class="p1">(<span class="default"><font color="Maroon" title="c2">S</font> <a href="ringfrac.html#NK17" title="RINGFRAC:NK.17">~</a> <font color="Maroon" title="c1">R</font></span>)</span>  ex <font color="Olive" title="b2">r1</font>, <font color="Olive" title="b3">r2</font> being   <a href="struct_0.html#NM1" title="STRUCT_0:NM.1">Element</a> of <font color="Maroon" title="c1">R</font> st <br/>( <font color="Olive" title="b3">r2</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a> <font color="Maroon" title="c2">S</font> &amp; <font color="Olive" title="b1">z</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="eqrel_1.html#K6" title="EQREL_1:func.6">Class</a> (<span class="p1">(<span class="default"><a href="ringfrac.html#K12" title="RINGFRAC:func.12">EqRel</a> <font color="Maroon" title="c2">S</font></span>)</span>,<span class="p1"><a href="domain_1.html#K1" title="DOMAIN_1:func.1">[</a><span class="default"><font color="Olive" title="b2">r1</font>,<font color="Olive" title="b3">r2</font></span><a href="domain_1.html#K1" title="DOMAIN_1:func.1">]</a></span>) )</span><br/><span class="kw">let </span><font color="Maroon" title="c3">z</font> be   <a href="struct_0.html#NM1" title="STRUCT_0:NM.1">Element</a> of <span class="p1">(<span class="default"><font color="Maroon" title="c2">S</font> <a href="ringfrac.html#NK17" title="RINGFRAC:NK.17">~</a> <font color="Maroon" title="c1">R</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">  ex <font color="Olive" title="b1">r1</font>, <font color="Olive" title="b2">r2</font> being   <a href="struct_0.html#NM1" title="STRUCT_0:NM.1">Element</a> of <font color="Maroon" title="c1">R</font> st <br/>( <font color="Olive" title="b2">r2</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a> <font color="Maroon" title="c2">S</font> &amp; <font color="Maroon" title="c3">z</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="eqrel_1.html#K6" title="EQREL_1:func.6">Class</a> (<span class="p1">(<span class="default"><a href="ringfrac.html#K12" title="RINGFRAC:func.12">EqRel</a> <font color="Maroon" title="c2">S</font></span>)</span>,<span class="p1"><a href="domain_1.html#K1" title="DOMAIN_1:func.1">[</a><span class="default"><font color="Olive" title="b1">r1</font>,<font color="Olive" title="b2">r2</font></span><a href="domain_1.html#K1" title="DOMAIN_1:func.1">]</a></span>) )</span><br/>





<span class="kw">consider </span><font color="Maroon" title="c4">r</font> being    <a href="subset_1.html#M2" title="SUBSET_1:mode.2">Element</a> of  <a href="ringfrac.html#K6" title="RINGFRAC:func.6">Frac</a> <font color="Maroon" title="c2">S</font><span class="kw"> such that </span><br/><a NAME="E2:73"/><span class="lab"><font color="Green" title="E50">A1</font></span>: 
<font color="Maroon" title="c3">z</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="eqrel_1.html#K6" title="EQREL_1:func.6">Class</a> (<span class="p1">(<span class="default"><a href="ringfrac.html#K12" title="RINGFRAC:func.12">EqRel</a> <font color="Maroon" title="c2">S</font></span>)</span>,<font color="Maroon" title="c4">r</font>)
 <span class="kw">by</span> <span class="lab"><a class="ref" href="ringfrac.html#T25" target="_self" onmouseover="rs('ringfrac/T25')" onmouseout="rh()">Th32</a></span>;<br/>
<span class="kw">consider </span><font color="Maroon" title="c5">r1</font>, <font color="Maroon" title="c6">r2</font> being   <a href="struct_0.html#NM1" title="STRUCT_0:NM.1">Element</a> of <font color="Maroon" title="c1">R</font><span class="kw"> such that </span><br/><a NAME="E4:73"/><span class="lab"><font color="Green" title="E51">A2</font></span>: 
<font color="Maroon" title="c5">r1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c4">r</font> <a href="domain_1.html#K2" title="DOMAIN_1:func.2">`1</a> 
 <span class="kw">and </span><br/><a NAME="E5:73"/><span class="lab"><font color="Green" title="E52">A3</font></span>: 
<font color="Maroon" title="c6">r2</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c4">r</font> <a href="domain_1.html#K3" title="DOMAIN_1:func.3">`2</a> 
 ;<br/>
<a NAME="E6:73"/>
<font color="Maroon" title="c3">z</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="eqrel_1.html#K6" title="EQREL_1:func.6">Class</a> (<span class="p1">(<span class="default"><a href="ringfrac.html#K12" title="RINGFRAC:func.12">EqRel</a> <font color="Maroon" title="c2">S</font></span>)</span>,<span class="p1"><a href="domain_1.html#K1" title="DOMAIN_1:func.1">[</a><span class="default"><font color="Maroon" title="c5">r1</font>,<font color="Maroon" title="c6">r2</font></span><a href="domain_1.html#K1" title="DOMAIN_1:func.1">]</a></span>)
 
<span class="kw">by</span> <span class="lab"><a class="txt" href="#E2:73"><span class="lab"><font color="Green" title="E50">A1</font></span></a>, <a class="txt" href="#E4:73"><span class="lab"><font color="Green" title="E51">A2</font></span></a>, <a class="txt" href="#E5:73"><span class="lab"><font color="Green" title="E52">A3</font></span></a></span>;<br/>
<span class="kw">hence </span><a NAME="E7:73"/>
 ex <font color="Olive" title="b1">r1</font>, <font color="Olive" title="b2">r2</font> being   <a href="struct_0.html#NM1" title="STRUCT_0:NM.1">Element</a> of <font color="Maroon" title="c1">R</font> st <br/>( <font color="Olive" title="b2">r2</font> <a href="tarski.html#R2" title="TARSKI:pred.2">in</a> <font color="Maroon" title="c2">S</font> &amp; <font color="Maroon" title="c3">z</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="eqrel_1.html#K6" title="EQREL_1:func.6">Class</a> (<span class="p1">(<span class="default"><a href="ringfrac.html#K12" title="RINGFRAC:func.12">EqRel</a> <font color="Maroon" title="c2">S</font></span>)</span>,<span class="p1"><a href="domain_1.html#K1" title="DOMAIN_1:func.1">[</a><span class="default"><font color="Olive" title="b1">r1</font>,<font color="Olive" title="b2">r2</font></span><a href="domain_1.html#K1" title="DOMAIN_1:func.1">]</a></span>) )
 <span class="kw">by</span> <span class="lab"><a class="txt" href="#E5:73"><span class="lab"><font color="Green" title="E52">A3</font></span></a>, <a class="txt" href="ringfrac.html#E25"><span class="lab"><font color="Green" title="E18">Lm17</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/>


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