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

<span class="kw">set </span><font color="Maroon" title="c1">T</font> =  <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a> ;<br/>
<a NAME="E1:73_1_1"/><span class="lab"><font color="Green" title="E41">a1</font></span>: 
 for <font color="Olive" title="b1">a</font>, <font color="Olive" title="b2">b</font> being   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a> holds  <font color="Olive" title="b1">a</font>,<font color="Olive" title="b2">b</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Olive" title="b2">b</font>,<font color="Olive" title="b1">a</font>
 
<div><a class="txt" onmouseover="tooltip.show('hs2',this)" onmouseout="tooltip.hide()" onclick="hs2(this)" href="javascript:()" title="73_1_1_1"><span class="kw">proof </span></a><div class="add">

<span class="kw">let </span><font color="Maroon" title="c2">a</font>, <font color="Maroon" title="c3">b</font> be   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</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"> <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c2">a</font></span><br/>

<a NAME="E1:73_1_1_1"/>
 <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c2">a</font>)
 
;<br/>
<span class="kw">hence </span><a NAME="E2:73_1_1_1"/>
<font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c2">a</font>
 <span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D15" target="_self" onmouseover="rs('gtarski1/D15')" onmouseout="rh()">NGDef</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>
<a NAME="E2:73_1_1"/><span class="lab"><font color="Green" title="E42">a2</font></span>: 
 for <font color="Olive" title="b1">a</font>, <font color="Olive" title="b2">b</font>, <font color="Olive" title="b3">p</font>, <font color="Olive" title="b4">q</font>, <font color="Olive" title="b5">r</font>, <font color="Olive" title="b6">s</font> being   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a>  st <font color="Olive" title="b1">a</font>,<font color="Olive" title="b2">b</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Olive" title="b3">p</font>,<font color="Olive" title="b4">q</font> &amp; <font color="Olive" title="b1">a</font>,<font color="Olive" title="b2">b</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Olive" title="b5">r</font>,<font color="Olive" title="b6">s</font> holds <br/><font color="Olive" title="b3">p</font>,<font color="Olive" title="b4">q</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Olive" title="b5">r</font>,<font color="Olive" title="b6">s</font>
 
<div><a class="txt" onmouseover="tooltip.show('hs2',this)" onmouseout="tooltip.hide()" onclick="hs2(this)" href="javascript:()" title="73_1_1_2"><span class="kw">proof </span></a><div class="add">

<span class="kw">let </span><font color="Maroon" title="c2">a</font>, <font color="Maroon" title="c3">b</font>, <font color="Maroon" title="c4">p</font>, <font color="Maroon" title="c5">q</font>, <font color="Maroon" title="c6">r</font>, <font color="Maroon" title="c7">s</font> be   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</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"> ( <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">q</font> &amp; <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c6">r</font>,<font color="Maroon" title="c7">s</font> implies <font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">q</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c6">r</font>,<font color="Maroon" title="c7">s</font> )</span><br/>

<span class="kw">assume </span><a NAME="E1:73_1_1_2"/>
( <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">q</font> &amp; <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c6">r</font>,<font color="Maroon" title="c7">s</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="c4">p</font>,<font color="Maroon" title="c5">q</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c6">r</font>,<font color="Maroon" title="c7">s</font></span><br/>

<a NAME="E2:73_1_1_2"/><span class="kw">then </span>
(  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">q</font>) &amp;  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c6">r</font>,<font color="Maroon" title="c7">s</font>) )
 
<span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D15" target="_self" onmouseover="rs('gtarski1/D15')" onmouseout="rh()">NGDef</a></span>;<br/>
<span class="kw">hence </span><a NAME="E3:73_1_1_2"/>
<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c5">q</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c6">r</font>,<font color="Maroon" title="c7">s</font>
 <span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D15" target="_self" onmouseover="rs('gtarski1/D15')" onmouseout="rh()">NGDef</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>
<a NAME="E3:73_1_1"/><span class="lab"><font color="Green" title="E43">a4</font></span>: 
 for <font color="Olive" title="b1">a</font>, <font color="Olive" title="b2">q</font>, <font color="Olive" title="b3">b</font>, <font color="Olive" title="b4">c</font> being   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a>  ex <font color="Olive" title="b5">x</font> being   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a> st <br/>(  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Olive" title="b2">q</font>,<font color="Olive" title="b1">a</font>,<font color="Olive" title="b5">x</font> &amp; <font color="Olive" title="b1">a</font>,<font color="Olive" title="b5">x</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Olive" title="b3">b</font>,<font color="Olive" title="b4">c</font> )
 
<div><a class="txt" onmouseover="tooltip.show('hs2',this)" onmouseout="tooltip.hide()" onclick="hs2(this)" href="javascript:()" title="73_1_1_3"><span class="kw">proof </span></a><div class="add">

<span class="kw">let </span><font color="Maroon" title="c2">a</font>, <font color="Maroon" title="c3">q</font>, <font color="Maroon" title="c4">b</font>, <font color="Maroon" title="c5">c</font> be   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</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">  ex <font color="Olive" title="b1">x</font> being   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a> st <br/>(  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c3">q</font>,<font color="Maroon" title="c2">a</font>,<font color="Olive" title="b1">x</font> &amp; <font color="Maroon" title="c2">a</font>,<font color="Olive" title="b1">x</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c4">b</font>,<font color="Maroon" title="c5">c</font> )</span><br/>

<span class="kw">take </span><font color="Maroon" title="c6">x</font> =  the   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</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"> (  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c3">q</font>,<font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c6">x</font> &amp; <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c6">x</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c4">b</font>,<font color="Maroon" title="c5">c</font> )</span><br/>

<a NAME="E1:73_1_1_3"/>
(  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c3">q</font>,<font color="Maroon" title="c2">a</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  &amp;  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c6">x</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  )
 
<span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D21" target="_self" onmouseover="rs('gtarski1/D21')" onmouseout="rh()">Lem1</a></span>;<br/>
<a NAME="E2:73_1_1_3"/><span class="kw">then </span><span class="lab"><font color="Green" title="E44">T1</font></span>: 
<font color="Maroon" title="c2">a</font> <a href="gtarski1.html#R5" title="GTARSKI1:pred.5">is_Between</a> <font color="Maroon" title="c3">q</font>,<font color="Maroon" title="c6">x</font>
 
<span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D21" target="_self" onmouseover="rs('gtarski1/D21')" onmouseout="rh()">Lem1</a></span>;<br/>
<a NAME="E3:73_1_1_3"/>
(  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c6">x</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  &amp;  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c4">b</font>,<font color="Maroon" title="c5">c</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  )
 
<span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D21" target="_self" onmouseover="rs('gtarski1/D21')" onmouseout="rh()">Lem1</a></span>;<br/>
<span class="kw">hence </span><a NAME="E4:73_1_1_3"/>
(  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c3">q</font>,<font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c6">x</font> &amp; <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c6">x</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c4">b</font>,<font color="Maroon" title="c5">c</font> )
 <span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D15" target="_self" onmouseover="rs('gtarski1/D15')" onmouseout="rh()">NGDef</a>, <a class="txt" href="#E2:73_1_1_3"><span class="lab"><font color="Green" title="E44">T1</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>
<a NAME="E4:73_1_1"/><span class="lab"><font color="Green" title="E44">a5</font></span>: 
 for <font color="Olive" title="b1">a</font>, <font color="Olive" title="b2">b</font>, <font color="Olive" title="b3">c</font>, <font color="Olive" title="b4">x</font>, <font color="Olive" title="b5">a9</font>, <font color="Olive" title="b6">b9</font>, <font color="Olive" title="b7">c9</font>, <font color="Olive" title="b8">x9</font> being   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a>  st <font color="Olive" title="b1">a</font> <a href="hidden.html#NR2" title="HIDDEN:NR.2">&lt;&gt;</a> <font color="Olive" title="b2">b</font> &amp; <font color="Olive" title="b1">a</font>,<font color="Olive" title="b2">b</font>,<font color="Olive" title="b3">c</font> <a href="gtarski1.html#R3" title="GTARSKI1:pred.3">cong</a> <font color="Olive" title="b5">a9</font>,<font color="Olive" title="b6">b9</font>,<font color="Olive" title="b7">c9</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Olive" title="b1">a</font>,<font color="Olive" title="b2">b</font>,<font color="Olive" title="b4">x</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Olive" title="b5">a9</font>,<font color="Olive" title="b6">b9</font>,<font color="Olive" title="b8">x9</font> &amp; <font color="Olive" title="b2">b</font>,<font color="Olive" title="b4">x</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Olive" title="b6">b9</font>,<font color="Olive" title="b8">x9</font> holds <br/><font color="Olive" title="b3">c</font>,<font color="Olive" title="b4">x</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Olive" title="b7">c9</font>,<font color="Olive" title="b8">x9</font>
 
<div><a class="txt" onmouseover="tooltip.show('hs2',this)" onmouseout="tooltip.hide()" onclick="hs2(this)" href="javascript:()" title="73_1_1_4"><span class="kw">proof </span></a><div class="add">

<span class="kw">let </span><font color="Maroon" title="c2">a</font>, <font color="Maroon" title="c3">b</font>, <font color="Maroon" title="c4">c</font>, <font color="Maroon" title="c5">x</font>, <font color="Maroon" title="c6">a9</font>, <font color="Maroon" title="c7">b9</font>, <font color="Maroon" title="c8">c9</font>, <font color="Maroon" title="c9">x9</font> be   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</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"> ( <font color="Maroon" title="c2">a</font> <a href="hidden.html#NR2" title="HIDDEN:NR.2">&lt;&gt;</a> <font color="Maroon" title="c3">b</font> &amp; <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c4">c</font> <a href="gtarski1.html#R3" title="GTARSKI1:pred.3">cong</a> <font color="Maroon" title="c6">a9</font>,<font color="Maroon" title="c7">b9</font>,<font color="Maroon" title="c8">c9</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c5">x</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c6">a9</font>,<font color="Maroon" title="c7">b9</font>,<font color="Maroon" title="c9">x9</font> &amp; <font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c5">x</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c7">b9</font>,<font color="Maroon" title="c9">x9</font> implies <font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">x</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c8">c9</font>,<font color="Maroon" title="c9">x9</font> )</span><br/>

<span class="kw">assume </span><a NAME="E1:73_1_1_4"/>
( <font color="Maroon" title="c2">a</font> <a href="hidden.html#NR2" title="HIDDEN:NR.2">&lt;&gt;</a> <font color="Maroon" title="c3">b</font> &amp; <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c4">c</font> <a href="gtarski1.html#R3" title="GTARSKI1:pred.3">cong</a> <font color="Maroon" title="c6">a9</font>,<font color="Maroon" title="c7">b9</font>,<font color="Maroon" title="c8">c9</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c5">x</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c6">a9</font>,<font color="Maroon" title="c7">b9</font>,<font color="Maroon" title="c9">x9</font> &amp; <font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c5">x</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c7">b9</font>,<font color="Maroon" title="c9">x9</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="c4">c</font>,<font color="Maroon" title="c5">x</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c8">c9</font>,<font color="Maroon" title="c9">x9</font></span><br/>

<a NAME="E2:73_1_1_4"/>
(  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">x</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  &amp;  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c8">c9</font>,<font color="Maroon" title="c9">x9</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  )
 
<span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D21" target="_self" onmouseover="rs('gtarski1/D21')" onmouseout="rh()">Lem1</a></span>;<br/>
<span class="kw">hence </span><a NAME="E3:73_1_1_4"/>
<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">x</font> <a href="gtarski1.html#R2" title="GTARSKI1:pred.2">equiv</a> <font color="Maroon" title="c8">c9</font>,<font color="Maroon" title="c9">x9</font>
 <span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D15" target="_self" onmouseover="rs('gtarski1/D15')" onmouseout="rh()">NGDef</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>
<a NAME="E5:73_1_1"/>
 for <font color="Olive" title="b1">a</font>, <font color="Olive" title="b2">b</font>, <font color="Olive" title="b3">p</font>, <font color="Olive" title="b4">q</font>, <font color="Olive" title="b5">z</font> being   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a>  st  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Olive" title="b1">a</font>,<font color="Olive" title="b3">p</font>,<font color="Olive" title="b5">z</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Olive" title="b2">b</font>,<font color="Olive" title="b4">q</font>,<font color="Olive" title="b5">z</font> holds <br/> ex <font color="Olive" title="b6">x</font> being   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a> st <br/>(  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Olive" title="b3">p</font>,<font color="Olive" title="b6">x</font>,<font color="Olive" title="b2">b</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Olive" title="b4">q</font>,<font color="Olive" title="b6">x</font>,<font color="Olive" title="b1">a</font> )
 
<div><a class="txt" onmouseover="tooltip.show('hs2',this)" onmouseout="tooltip.hide()" onclick="hs2(this)" href="javascript:()" title="73_1_1_5"><span class="kw">proof </span></a><div class="add">

<span class="kw">let </span><font color="Maroon" title="c2">a</font>, <font color="Maroon" title="c3">b</font>, <font color="Maroon" title="c4">p</font>, <font color="Maroon" title="c5">q</font>, <font color="Maroon" title="c6">z</font> be   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</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"> (  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c6">z</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c5">q</font>,<font color="Maroon" title="c6">z</font> implies  ex <font color="Olive" title="b1">x</font> being   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a> st <br/>(  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c4">p</font>,<font color="Olive" title="b1">x</font>,<font color="Maroon" title="c3">b</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c5">q</font>,<font color="Olive" title="b1">x</font>,<font color="Maroon" title="c2">a</font> ) )</span><br/>

<span class="kw">assume </span><a NAME="E1:73_1_1_5"/>
(  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c2">a</font>,<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c6">z</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c3">b</font>,<font color="Maroon" title="c5">q</font>,<font color="Maroon" title="c6">z</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">  ex <font color="Olive" title="b1">x</font> being   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a> st <br/>(  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c4">p</font>,<font color="Olive" title="b1">x</font>,<font color="Maroon" title="c3">b</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c5">q</font>,<font color="Olive" title="b1">x</font>,<font color="Maroon" title="c2">a</font> )</span><br/>

<span class="kw">take </span><font color="Maroon" title="c7">x</font> =  the   <a href="gtarski1.html#NM1" title="GTARSKI1:NM.1">POINT</a> of <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</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"> (  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c7">x</font>,<font color="Maroon" title="c3">b</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c5">q</font>,<font color="Maroon" title="c7">x</font>,<font color="Maroon" title="c2">a</font> )</span><br/>

<a NAME="E2:73_1_1_5"/><span class="lab"><font color="Green" title="E45">s2</font></span>: 
(  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c3">b</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  &amp;  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c7">x</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  &amp;  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c7">x</font>,<font color="Maroon" title="c3">b</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  )
 
<span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D21" target="_self" onmouseover="rs('gtarski1/D21')" onmouseout="rh()">Lem1</a></span>;<br/>
<a NAME="E3:73_1_1_5"/>
(  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c5">q</font>,<font color="Maroon" title="c2">a</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  &amp;  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c5">q</font>,<font color="Maroon" title="c7">x</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  &amp;  <a href="metric_1.html#K3" title="METRIC_1:func.3">dist</a> (<font color="Maroon" title="c7">x</font>,<font color="Maroon" title="c2">a</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="ordinal1.html#K5" title="ORDINAL1:func.5">0</a>  )
 
<span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D21" target="_self" onmouseover="rs('gtarski1/D21')" onmouseout="rh()">Lem1</a></span>;<br/>
<a NAME="E4:73_1_1_5"/><span class="kw">then </span>
( <font color="Maroon" title="c7">x</font> <a href="gtarski1.html#R5" title="GTARSKI1:pred.5">is_Between</a> <font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c3">b</font> &amp; <font color="Maroon" title="c7">x</font> <a href="gtarski1.html#R5" title="GTARSKI1:pred.5">is_Between</a> <font color="Maroon" title="c5">q</font>,<font color="Maroon" title="c2">a</font> )
 
<span class="kw">by</span> <span class="lab"><a class="txt" href="#E2:73_1_1_5"><span class="lab"><font color="Green" title="E45">s2</font></span></a></span>;<br/>
<span class="kw">hence </span><a NAME="E5:73_1_1_5"/>
(  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c4">p</font>,<font color="Maroon" title="c7">x</font>,<font color="Maroon" title="c3">b</font> &amp;  <a href="gtarski1.html#R1" title="GTARSKI1:pred.1">between</a> <font color="Maroon" title="c5">q</font>,<font color="Maroon" title="c7">x</font>,<font color="Maroon" title="c2">a</font> )
 <span class="kw">by</span> <span class="lab"><a class="ref" href="gtarski1.html#D15" target="_self" onmouseover="rs('gtarski1/D15')" onmouseout="rh()">NGDef</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="E6:73_1_1"/>
(  <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a>  is  <a href="gtarski1.html#V2" title="GTARSKI1:attr.2">satisfying_CongruenceSymmetry</a>  &amp;  <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a>  is  <a href="gtarski1.html#V3" title="GTARSKI1:attr.3">satisfying_CongruenceEquivalenceRelation</a>  &amp;  <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a>  is  <a href="gtarski1.html#V5" title="GTARSKI1:attr.5">satisfying_SegmentConstruction</a>  &amp;  <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a>  is  <a href="gtarski1.html#V6" title="GTARSKI1:attr.6">satisfying_SAS</a>  &amp;  <a href="gtarski1.html#K2" title="GTARSKI1:func.2">Tarski0Space</a>  is  <a href="gtarski1.html#V8" title="GTARSKI1:attr.8">satisfying_Pasch</a>  )
 <span class="kw">by</span> <span class="lab"><a class="txt" href="#E1:73_1_1"><span class="lab"><font color="Green" title="E41">a1</font></span></a>, <a class="txt" href="#E2:73_1_1"><span class="lab"><font color="Green" title="E42">a2</font></span></a>, <a class="txt" href="#E3:73_1_1"><span class="lab"><font color="Green" title="E43">a4</font></span></a>, <a class="txt" href="#E4:73_1_1"><span class="lab"><font color="Green" title="E44">a5</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>
