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<b>let </b><font color="Maroon" title="c1">FT</font> be  non <a href="struct_0.html#V3" title="STRUCT_0:attr.3">empty</a>  <a href="orders_2.html#L1" title="ORDERS_2:struct.1">RelStr</a> ;<br/><b>let </b><font color="Maroon" title="c2">A</font>, <font color="Maroon" title="c3">C</font> be   <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <font color="Maroon" title="c1">FT</font>;<br/><b>let </b><font color="Maroon" title="c4">D</font> be  non <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a> <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <font color="Maroon" title="c1">FT</font>;<br/>







<b>assume </b><b>that </b><br/><a NAME="E1:55"/><i><font color="Green" title="E30">A1</font></i>: 
( <font color="Maroon" title="c1">FT</font> is <a href="fin_topo.html#V1" title="FIN_TOPO:attr.1">filled</a> &amp; <font color="Maroon" title="c1">FT</font> is <a href="fin_topo.html#V2" title="FIN_TOPO:attr.2">symmetric</a> &amp; <font color="Maroon" title="c4">D</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1">(<span class="default"><a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <font color="Maroon" title="c1">FT</font></span>)</span> <a href="subset_1.html#K7" title="SUBSET_1:func.7">\</a> <font color="Maroon" title="c2">A</font> &amp; <font color="Maroon" title="c1">FT</font> is <a href="fintopo6.html#V1" title="FINTOPO6:attr.1">connected</a> )
 <b>and </b><br/><a NAME="E2:55"/><i><font color="Green" title="E31">A2</font></i>: 
<font color="Maroon" title="c2">A</font> is <a href="fin_topo.html#V5" title="FIN_TOPO:attr.5">connected</a>
 <b>and </b><br/><a NAME="E3:55"/><i><font color="Green" title="E32">A3</font></i>: 
<font color="Maroon" title="c3">C</font> <a href="fintopo6.html#R2" title="FINTOPO6:pred.2">is_a_component_of</a> <font color="Maroon" title="c4">D</font>
 ;<br/>

<b>consider </b><font color="Maroon" title="c5">C1</font> being   <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <span class="p1">(<span class="default"><font color="Maroon" title="c1">FT</font> <a href="fintopo6.html#K1" title="FINTOPO6:func.1">|</a> <font color="Maroon" title="c4">D</font></span>)</span><b> such that </b><br/><a NAME="E5:55"/><i><font color="Green" title="E33">A4</font></i>: 
<font color="Maroon" title="c5">C1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c3">C</font>
 <b>and </b><br/><a NAME="E6:55"/><i><font color="Green" title="E34">A5</font></i>: 
<font color="Maroon" title="c5">C1</font> <a href="fintopo6.html#R1" title="FINTOPO6:pred.1">is_a_component_of</a> <font color="Maroon" title="c1">FT</font> <a href="fintopo6.html#K1" title="FINTOPO6:func.1">|</a> <font color="Maroon" title="c4">D</font>
 <b>by </b><i><a class="txt" href="fintopo6.html#E3:55"><i><font color="Green" title="E32">A3</font></i></a>, <a class="ref" href="fintopo6.html#D5" target="_self" title="FINTOPO6:def.5">Def5</a></i>;<br/>
<a NAME="E7:55"/><i><font color="Green" title="E35">A6</font></i>: 
<font color="Maroon" title="c5">C1</font> is <a href="fin_topo.html#V5" title="FIN_TOPO:attr.5">connected</a>
 
<b>by </b><i><a class="txt" href="fintopo6.html#E6:55"><i><font color="Green" title="E34">A5</font></i></a>, <a class="ref" href="fintopo6.html#D4" target="_self" title="FINTOPO6:def.4">Def4</a></i>;<br/>
<b>reconsider </b><font color="Maroon" title="c6">C2</font> = <font color="Maroon" title="c5">C1</font> as   <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <font color="Maroon" title="c1">FT</font> <b>by </b><i><a class="txt" href="fintopo6.html#E5:55"><i><font color="Green" title="E33">A4</font></i></a></i>;<br/>
<a NAME="E9:55"/>
<font color="Maroon" title="c5">C1</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a>  <a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <span class="p1">(<span class="default"><font color="Maroon" title="c1">FT</font> <a href="fintopo6.html#K1" title="FINTOPO6:func.1">|</a> <font color="Maroon" title="c4">D</font></span>)</span>
 
;<br/>
<a NAME="E10:55"/><b>then </b>
<font color="Maroon" title="c5">C1</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <span class="p1">(<span class="default"><a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <font color="Maroon" title="c1">FT</font></span>)</span> <a href="subset_1.html#K7" title="SUBSET_1:func.7">\</a> <font color="Maroon" title="c2">A</font>
 
<b>by </b><i><a class="txt" href="fintopo6.html#E1:55"><i><font color="Green" title="E30">A1</font></i></a>, <a class="ref" href="fintopo6.html#D3" target="_self" title="FINTOPO6:def.3">Def3</a></i>;<br/>
<a NAME="E11:55"/><b>then </b><i><font color="Green" title="E36">A7</font></i>: 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <font color="Maroon" title="c1">FT</font></span>)</span> <a href="subset_1.html#K7" title="SUBSET_1:func.7">\</a> <font color="Maroon" title="c2">A</font></span>)</span> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a>  <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c6">C2</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> 
 
<b>by </b><i><a class="ref" href="subset_1.html#T31" title="SUBSET_1:th.31">SUBSET_1:31</a></i>;<br/>
<a NAME="E12:55"/><b>then </b><i><font color="Green" title="E37">A8</font></i>: 
<font color="Maroon" title="c2">A</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c6">C2</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> 
 
<b>by </b><i><a class="ref" href="pre_topc.html#T22" title="PRE_TOPC:th.22">PRE_TOPC:22</a></i>;<br/>
<a NAME="E13:55"/><i><font color="Green" title="E38">A9</font></i>: 
<font color="Maroon" title="c2">A</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <span class="p1">(<span class="default"><a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <font color="Maroon" title="c1">FT</font></span>)</span> <a href="subset_1.html#K7" title="SUBSET_1:func.7">\</a> <font color="Maroon" title="c6">C2</font>
 
<b>by </b><i><a class="txt" href="fintopo6.html#E11:55"><i><font color="Green" title="E36">A7</font></i></a>, <a class="ref" href="pre_topc.html#T22" title="PRE_TOPC:th.22">PRE_TOPC:22</a></i>;<br/>
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="55_1"><b>now </b></a><div class="add"><b>let </b><font color="Maroon" title="c7">P</font>, <font color="Maroon" title="c8">Q</font> be   <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <font color="Maroon" title="c1">FT</font>;<br/><b>assume </b><b>that </b><br/><a NAME="E1:55_1"/><i><font color="Green" title="E39">A10</font></i>: 
<span class="p1">(<span class="default"><a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <font color="Maroon" title="c1">FT</font></span>)</span> <a href="subset_1.html#K7" title="SUBSET_1:func.7">\</a> <font color="Maroon" title="c3">C</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c7">P</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c8">Q</font>
 <b>and </b><br/><a NAME="E2:55_1"/><i><font color="Green" title="E40">A11</font></i>: 
<font color="Maroon" title="c7">P</font> <a href="xboole_0.html#R1" title="XBOOLE_0:pred.1">misses</a> <font color="Maroon" title="c8">Q</font>
 <b>and </b><br/><a NAME="E3:55_1"/><i><font color="Green" title="E41">A12</font></i>: 
<font color="Maroon" title="c7">P</font>,<font color="Maroon" title="c8">Q</font> <a href="fintopo4.html#R1" title="FINTOPO4:pred.1">are_separated</a> 
 ;<br/><a NAME="E4:55_1"/><i><font color="Green" title="E42">A13</font></i>: 
<font color="Maroon" title="c8">Q</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <span class="p1">(<span class="default"><a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <font color="Maroon" title="c1">FT</font></span>)</span> <a href="subset_1.html#K7" title="SUBSET_1:func.7">\</a> <font color="Maroon" title="c3">C</font>
 <b>by </b><i><a class="txt" href="fintopo6.html#E1:55_1"><i><font color="Green" title="E39">A10</font></i></a>, <a class="ref" href="xboole_1.html#T7" title="XBOOLE_1:th.7">XBOOLE_1:7</a></i>;<br/><a NAME="E5:55_1"/>
<font color="Maroon" title="c2">A</font> <a href="xboole_0.html#R1" title="XBOOLE_0:pred.1">misses</a> <font color="Maroon" title="c5">C1</font>
 <b>by </b><i><a class="txt" href="fintopo6.html#E12:55"><i><font color="Green" title="E37">A8</font></i></a>, <a class="ref" href="subset_1.html#T43" title="SUBSET_1:th.43">SUBSET_1:43</a></i>;<br/><a NAME="E6:55_1"/><b>then </b><i><font color="Green" title="E43">A14</font></i>: 
<font color="Maroon" title="c2">A</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c5">C1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
 <b>by </b><i><a class="ref" href="xboole_0.html#D7" title="XBOOLE_0:def.7">XBOOLE_0:def 7</a></i>;<br/><a NAME="E7:55_1"/><i><font color="Green" title="E44">A15</font></i>: 
<font color="Maroon" title="c3">C</font> is <a href="fin_topo.html#V5" title="FIN_TOPO:attr.5">connected</a>
 <b>by </b><i><a class="txt" href="fintopo6.html#E1:55"><i><font color="Green" title="E30">A1</font></i></a>, <a class="txt" href="fintopo6.html#E5:55"><i><font color="Green" title="E33">A4</font></i></a>, <a class="txt" href="fintopo6.html#E7:55"><i><font color="Green" title="E35">A6</font></i></a>, <a class="ref" href="fintopo6.html#T38" target="_self" title="FINTOPO6:th.38">Th38</a></i>;<br/><a NAME="E8:55_1"/><i><font color="Green" title="E45">A16</font></i>: 
<font color="Maroon" title="c7">P</font> <a href="xboole_0.html#R1" title="XBOOLE_0:pred.1">misses</a> <font color="Maroon" title="c7">P</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> 
 <b>by </b><i><a class="ref" href="xboole_1.html#T79" title="XBOOLE_1:th.79">XBOOLE_1:79</a></i>;<br/><div><i><font color="Green" title="E46">A17</font></i>: <a class="txt" onclick="hs2(this)" href="javascript:()" title="55_1_1"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:55_1_1"/><i><font color="Green" title="E47">A18</font></i>: 
<font color="Maroon" title="c2">A</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c7">P</font>
 ;<br/><a NAME="E2:55_1_1"/>
<font color="Maroon" title="c8">Q</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c7">P</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> 
 <b>by </b><i><a class="txt" href="fintopo6.html#E2:55_1"><i><font color="Green" title="E40">A11</font></i></a>, <a class="ref" href="subset_1.html#T43" title="SUBSET_1:th.43">SUBSET_1:43</a></i>;<br/><a NAME="E3:55_1_1"/><b>then </b>
<font color="Maroon" title="c2">A</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c8">Q</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c7">P</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <span class="p1">(<span class="default"><font color="Maroon" title="c7">P</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> </span>)</span>
 <b>by </b><i><a class="txt" href="fintopo6.html#E1:55_1_1"><i><font color="Green" title="E47">A18</font></i></a>, <a class="ref" href="xboole_1.html#T27" title="XBOOLE_1:th.27">XBOOLE_1:27</a></i>;<br/><a NAME="E4:55_1_1"/><b>then </b><i><font color="Green" title="E48">A19</font></i>: 
<font color="Maroon" title="c2">A</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c8">Q</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
 <b>by </b><i><a class="txt" href="fintopo6.html#E8:55_1"><i><font color="Green" title="E45">A16</font></i></a>, <a class="ref" href="xboole_0.html#D7" title="XBOOLE_0:def.7">XBOOLE_0:def 7</a></i>;<br/><span class="p1">(<span class="default"><font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c8">Q</font></span>)</span> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c2">A</font> = 
<span class="p1">(<span class="default"><font color="Maroon" title="c2">A</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c3">C</font></span>)</span> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <span class="p1">(<span class="default"><font color="Maroon" title="c2">A</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c8">Q</font></span>)</span>
<b>by </b><i><a class="ref" href="xboole_1.html#T23" title="XBOOLE_1:th.23">XBOOLE_1:23</a></i>
<br/>.= 
 <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
<b>by </b><i><a class="txt" href="fintopo6.html#E5:55"><i><font color="Green" title="E33">A4</font></i></a>, <a class="txt" href="fintopo6.html#E6:55_1"><i><font color="Green" title="E43">A14</font></i></a>, <a class="txt" href="fintopo6.html#E4:55_1_1"><i><font color="Green" title="E48">A19</font></i></a>, <a class="ref" href="xboole_1.html#T3" title="XBOOLE_1:th.3">XBOOLE_1:3</a></i>
;<br/><a NAME="E6:55_1_1"/><b>then </b>
<font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c8">Q</font> <a href="xboole_0.html#R1" title="XBOOLE_0:pred.1">misses</a> <font color="Maroon" title="c2">A</font>
 <b>by </b><i><a class="ref" href="xboole_0.html#D7" title="XBOOLE_0:def.7">XBOOLE_0:def 7</a></i>;<br/><a NAME="E7:55_1_1"/><b>then </b>
<font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c8">Q</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c2">A</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> 
 <b>by </b><i><a class="ref" href="subset_1.html#T43" title="SUBSET_1:th.43">SUBSET_1:43</a></i>;<br/><a NAME="E8:55_1_1"/><b>then </b>
<font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c8">Q</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a>  <a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <span class="p1">(<span class="default"><font color="Maroon" title="c1">FT</font> <a href="fintopo6.html#K1" title="FINTOPO6:func.1">|</a> <font color="Maroon" title="c4">D</font></span>)</span>
 <b>by </b><i><a class="ref" href="fintopo6.html#D3" target="_self" title="FINTOPO6:def.3">Def3</a>, <a class="txt" href="fintopo6.html#E1:55"><i><font color="Green" title="E30">A1</font></i></a></i>;<br/><b>then reconsider </b><font color="Maroon" title="c9">C1Q1</font> = <font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c8">Q</font> as   <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <span class="p1">(<span class="default"><font color="Maroon" title="c1">FT</font> <a href="fintopo6.html#K1" title="FINTOPO6:func.1">|</a> <font color="Maroon" title="c4">D</font></span>)</span> ;<br/><a NAME="E10:55_1_1"/>
<font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c8">Q</font> is <a href="fin_topo.html#V5" title="FIN_TOPO:attr.5">connected</a>
 <b>by </b><i><a class="txt" href="fintopo6.html#E1:55"><i><font color="Green" title="E30">A1</font></i></a>, <a class="txt" href="fintopo6.html#E1:55_1"><i><font color="Green" title="E39">A10</font></i></a>, <a class="txt" href="fintopo6.html#E3:55_1"><i><font color="Green" title="E41">A12</font></i></a>, <a class="txt" href="fintopo6.html#E7:55_1"><i><font color="Green" title="E44">A15</font></i></a>, <a class="ref" href="fintopo6.html#T37" target="_self" title="FINTOPO6:th.37">Th37</a></i>;<br/><a NAME="E11:55_1_1"/><b>then </b><i><font color="Green" title="E49">A20</font></i>: 
<font color="Maroon" title="c9">C1Q1</font> is <a href="fin_topo.html#V5" title="FIN_TOPO:attr.5">connected</a>
 <b>by </b><i><a class="ref" href="fintopo6.html#T38" target="_self" title="FINTOPO6:th.38">Th38</a>, <a class="txt" href="fintopo6.html#E1:55"><i><font color="Green" title="E30">A1</font></i></a></i>;<br/><a NAME="E12:55_1_1"/><i><font color="Green" title="E50">A21</font></i>: 
<font color="Maroon" title="c3">C</font> <a href="xboole_0.html#R1" title="XBOOLE_0:pred.1">misses</a> <font color="Maroon" title="c3">C</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> 
 <b>by </b><i><a class="ref" href="xboole_1.html#T79" title="XBOOLE_1:th.79">XBOOLE_1:79</a></i>;<br/><a NAME="E13:55_1_1"/>
<font color="Maroon" title="c5">C1</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c5">C1</font> <a href="xboole_0.html#K2" title="XBOOLE_0:func.2">\/</a> <font color="Maroon" title="c8">Q</font>
 <b>by </b><i><a class="ref" href="xboole_1.html#T7" title="XBOOLE_1:th.7">XBOOLE_1:7</a></i>;<br/><a NAME="E14:55_1_1"/><b>then </b>
<font color="Maroon" title="c9">C1Q1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c5">C1</font>
 <b>by </b><i><a class="txt" href="fintopo6.html#E5:55"><i><font color="Green" title="E33">A4</font></i></a>, <a class="txt" href="fintopo6.html#E6:55"><i><font color="Green" title="E34">A5</font></i></a>, <a class="txt" href="fintopo6.html#E11:55_1_1"><i><font color="Green" title="E49">A20</font></i></a>, <a class="ref" href="fintopo6.html#D4" target="_self" title="FINTOPO6:def.4">Def4</a></i>;<br/><a NAME="E15:55_1_1"/><b>then </b>
<font color="Maroon" title="c8">Q</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c3">C</font>
 <b>by </b><i><a class="txt" href="fintopo6.html#E5:55"><i><font color="Green" title="E33">A4</font></i></a>, <a class="ref" href="xboole_1.html#T7" title="XBOOLE_1:th.7">XBOOLE_1:7</a></i>;<br/><a NAME="E16:55_1_1"/><b>then </b>
<font color="Maroon" title="c8">Q</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c3">C</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <font color="Maroon" title="c1">FT</font></span>)</span> <a href="subset_1.html#K7" title="SUBSET_1:func.7">\</a> <font color="Maroon" title="c3">C</font></span>)</span>
 <b>by </b><i><a class="txt" href="fintopo6.html#E4:55_1"><i><font color="Green" title="E42">A13</font></i></a>, <a class="ref" href="xboole_1.html#T19" title="XBOOLE_1:th.19">XBOOLE_1:19</a></i>;<br/><a NAME="E17:55_1_1"/><b>then </b>
<font color="Maroon" title="c8">Q</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
 <b>by </b><i><a class="txt" href="fintopo6.html#E12:55_1_1"><i><font color="Green" title="E50">A21</font></i></a>, <a class="ref" href="xboole_0.html#D7" title="XBOOLE_0:def.7">XBOOLE_0:def 7</a></i>;<br/><b>hence </b><a NAME="E18:55_1_1"/>
<font color="Maroon" title="c8">Q</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="struct_0.html#K1" title="STRUCT_0:func.1">{}</a> <font color="Maroon" title="c1">FT</font>
 <b>by </b><i><a class="ref" href="xboole_1.html#T3" title="XBOOLE_1:th.3">XBOOLE_1:3</a></i>;<br/></div><b>end;</b></div><div><a class="txt" onclick="hs2(this)" href="javascript:()" title="55_1_2"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:55_1_2"/><i><font color="Green" title="E47">A22</font></i>: 
<font color="Maroon" title="c2">A</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c8">Q</font>
 ;<br/><a NAME="E2:55_1_2"/><i><font color="Green" title="E48">A23</font></i>: 
<font color="Maroon" title="c8">Q</font> <a href="xboole_0.html#R1" title="XBOOLE_0:pred.1">misses</a> <font color="Maroon" title="c8">Q</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> 
 <b>by </b><i><a class="ref" href="xboole_1.html#T79" title="XBOOLE_1:th.79">XBOOLE_1:79</a></i>;<br/><a NAME="E3:55_1_2"/>
<font color="Maroon" title="c7">P</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c8">Q</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> 
 <b>by </b><i><a class="txt" href="fintopo6.html#E2:55_1"><i><font color="Green" title="E40">A11</font></i></a>, <a class="ref" href="subset_1.html#T43" title="SUBSET_1:th.43">SUBSET_1:43</a></i>;<br/><a NAME="E4:55_1_2"/><b>then </b>
<font color="Maroon" title="c2">A</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c7">P</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c8">Q</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <span class="p1">(<span class="default"><font color="Maroon" title="c8">Q</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> </span>)</span>
 <b>by </b><i><a class="txt" href="fintopo6.html#E1:55_1_2"><i><font color="Green" title="E47">A22</font></i></a>, <a class="ref" href="xboole_1.html#T27" title="XBOOLE_1:th.27">XBOOLE_1:27</a></i>;<br/><a NAME="E5:55_1_2"/><b>then </b><i><font color="Green" title="E49">A24</font></i>: 
<font color="Maroon" title="c2">A</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c7">P</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
 <b>by </b><i><a class="txt" href="fintopo6.html#E2:55_1_2"><i><font color="Green" title="E48">A23</font></i></a>, <a class="ref" href="xboole_0.html#D7" title="XBOOLE_0:def.7">XBOOLE_0:def 7</a></i>;<br/><span class="p1">(<span class="default"><font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c7">P</font></span>)</span> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c2">A</font> = 
<span class="p1">(<span class="default"><font color="Maroon" title="c2">A</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c3">C</font></span>)</span> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <span class="p1">(<span class="default"><font color="Maroon" title="c2">A</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <font color="Maroon" title="c7">P</font></span>)</span>
<b>by </b><i><a class="ref" href="xboole_1.html#T23" title="XBOOLE_1:th.23">XBOOLE_1:23</a></i>
<br/>.= 
 <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
<b>by </b><i><a class="txt" href="fintopo6.html#E5:55"><i><font color="Green" title="E33">A4</font></i></a>, <a class="txt" href="fintopo6.html#E6:55_1"><i><font color="Green" title="E43">A14</font></i></a>, <a class="txt" href="fintopo6.html#E5:55_1_2"><i><font color="Green" title="E49">A24</font></i></a>, <a class="ref" href="xboole_1.html#T3" title="XBOOLE_1:th.3">XBOOLE_1:3</a></i>
;<br/><a NAME="E7:55_1_2"/><b>then </b>
<font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c7">P</font> <a href="xboole_0.html#R1" title="XBOOLE_0:pred.1">misses</a> <font color="Maroon" title="c2">A</font>
 <b>by </b><i><a class="ref" href="xboole_0.html#D7" title="XBOOLE_0:def.7">XBOOLE_0:def 7</a></i>;<br/><a NAME="E8:55_1_2"/><b>then </b>
<font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c7">P</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c2">A</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> 
 <b>by </b><i><a class="ref" href="subset_1.html#T43" title="SUBSET_1:th.43">SUBSET_1:43</a></i>;<br/><a NAME="E9:55_1_2"/><b>then </b>
<font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c7">P</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a>  <a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <span class="p1">(<span class="default"><font color="Maroon" title="c1">FT</font> <a href="fintopo6.html#K1" title="FINTOPO6:func.1">|</a> <font color="Maroon" title="c4">D</font></span>)</span>
 <b>by </b><i><a class="ref" href="fintopo6.html#D3" target="_self" title="FINTOPO6:def.3">Def3</a>, <a class="txt" href="fintopo6.html#E1:55"><i><font color="Green" title="E30">A1</font></i></a></i>;<br/><b>then reconsider </b><font color="Maroon" title="c9">C1P1</font> = <font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c7">P</font> as   <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <span class="p1">(<span class="default"><font color="Maroon" title="c1">FT</font> <a href="fintopo6.html#K1" title="FINTOPO6:func.1">|</a> <font color="Maroon" title="c4">D</font></span>)</span> ;<br/><a NAME="E11:55_1_2"/>
<font color="Maroon" title="c3">C</font> <a href="subset_1.html#K4" title="SUBSET_1:func.4">\/</a> <font color="Maroon" title="c7">P</font> is <a href="fin_topo.html#V5" title="FIN_TOPO:attr.5">connected</a>
 <b>by </b><i><a class="txt" href="fintopo6.html#E1:55"><i><font color="Green" title="E30">A1</font></i></a>, <a class="txt" href="fintopo6.html#E1:55_1"><i><font color="Green" title="E39">A10</font></i></a>, <a class="txt" href="fintopo6.html#E3:55_1"><i><font color="Green" title="E41">A12</font></i></a>, <a class="txt" href="fintopo6.html#E7:55_1"><i><font color="Green" title="E44">A15</font></i></a>, <a class="ref" href="fintopo6.html#T37" target="_self" title="FINTOPO6:th.37">Th37</a></i>;<br/><a NAME="E12:55_1_2"/><b>then </b><i><font color="Green" title="E50">A25</font></i>: 
<font color="Maroon" title="c9">C1P1</font> is <a href="fin_topo.html#V5" title="FIN_TOPO:attr.5">connected</a>
 <b>by </b><i><a class="ref" href="fintopo6.html#T38" target="_self" title="FINTOPO6:th.38">Th38</a>, <a class="txt" href="fintopo6.html#E1:55"><i><font color="Green" title="E30">A1</font></i></a></i>;<br/><a NAME="E13:55_1_2"/>
<font color="Maroon" title="c3">C</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c5">C1</font> <a href="xboole_0.html#K2" title="XBOOLE_0:func.2">\/</a> <font color="Maroon" title="c7">P</font>
 <b>by </b><i><a class="txt" href="fintopo6.html#E5:55"><i><font color="Green" title="E33">A4</font></i></a>, <a class="ref" href="xboole_1.html#T7" title="XBOOLE_1:th.7">XBOOLE_1:7</a></i>;<br/><a NAME="E14:55_1_2"/><b>then </b>
<font color="Maroon" title="c9">C1P1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c5">C1</font>
 <b>by </b><i><a class="txt" href="fintopo6.html#E5:55"><i><font color="Green" title="E33">A4</font></i></a>, <a class="txt" href="fintopo6.html#E6:55"><i><font color="Green" title="E34">A5</font></i></a>, <a class="txt" href="fintopo6.html#E12:55_1_2"><i><font color="Green" title="E50">A25</font></i></a>, <a class="ref" href="fintopo6.html#D4" target="_self" title="FINTOPO6:def.4">Def4</a></i>;<br/><a NAME="E15:55_1_2"/><b>then </b><i><font color="Green" title="E51">A26</font></i>: 
<font color="Maroon" title="c7">P</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c3">C</font>
 <b>by </b><i><a class="txt" href="fintopo6.html#E5:55"><i><font color="Green" title="E33">A4</font></i></a>, <a class="ref" href="xboole_1.html#T7" title="XBOOLE_1:th.7">XBOOLE_1:7</a></i>;<br/><a NAME="E16:55_1_2"/><i><font color="Green" title="E52">A27</font></i>: 
<font color="Maroon" title="c3">C</font> <a href="xboole_0.html#R1" title="XBOOLE_0:pred.1">misses</a> <font color="Maroon" title="c3">C</font> <a href="subset_1.html#K3" title="SUBSET_1:func.3">`</a> 
 <b>by </b><i><a class="ref" href="xboole_1.html#T79" title="XBOOLE_1:th.79">XBOOLE_1:79</a></i>;<br/><a NAME="E17:55_1_2"/>
<font color="Maroon" title="c7">P</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <span class="p1">(<span class="default"><a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <font color="Maroon" title="c1">FT</font></span>)</span> <a href="subset_1.html#K7" title="SUBSET_1:func.7">\</a> <font color="Maroon" title="c3">C</font>
 <b>by </b><i><a class="txt" href="fintopo6.html#E1:55_1"><i><font color="Green" title="E39">A10</font></i></a>, <a class="ref" href="xboole_1.html#T7" title="XBOOLE_1:th.7">XBOOLE_1:7</a></i>;<br/><a NAME="E18:55_1_2"/><b>then </b>
<font color="Maroon" title="c7">P</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Maroon" title="c3">C</font> <a href="subset_1.html#K9" title="SUBSET_1:func.9">/\</a> <span class="p1">(<span class="default"><span class="p2">(<span class="default"><a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <font color="Maroon" title="c1">FT</font></span>)</span> <a href="subset_1.html#K7" title="SUBSET_1:func.7">\</a> <font color="Maroon" title="c3">C</font></span>)</span>
 <b>by </b><i><a class="txt" href="fintopo6.html#E15:55_1_2"><i><font color="Green" title="E51">A26</font></i></a>, <a class="ref" href="xboole_1.html#T19" title="XBOOLE_1:th.19">XBOOLE_1:19</a></i>;<br/><a NAME="E19:55_1_2"/><b>then </b>
<font color="Maroon" title="c7">P</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
 <b>by </b><i><a class="txt" href="fintopo6.html#E16:55_1_2"><i><font color="Green" title="E52">A27</font></i></a>, <a class="ref" href="xboole_0.html#D7" title="XBOOLE_0:def.7">XBOOLE_0:def 7</a></i>;<br/><b>hence </b><a NAME="E20:55_1_2"/>
<font color="Maroon" title="c7">P</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="struct_0.html#K1" title="STRUCT_0:func.1">{}</a> <font color="Maroon" title="c1">FT</font>
 <b>by </b><i><a class="ref" href="xboole_1.html#T3" title="XBOOLE_1:th.3">XBOOLE_1:3</a></i>;<br/></div><b>end;</b></div><b>hence </b><a NAME="E11:55_1"/>
( <font color="Maroon" title="c7">P</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="struct_0.html#K1" title="STRUCT_0:func.1">{}</a> <font color="Maroon" title="c1">FT</font> or <font color="Maroon" title="c8">Q</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="struct_0.html#K1" title="STRUCT_0:func.1">{}</a> <font color="Maroon" title="c1">FT</font> )
 <b>by </b><i><a class="txt" href="fintopo6.html#E1:55"><i><font color="Green" title="E30">A1</font></i></a>, <a class="txt" href="fintopo6.html#E2:55"><i><font color="Green" title="E31">A2</font></i></a>, <a class="txt" href="fintopo6.html#E5:55"><i><font color="Green" title="E33">A4</font></i></a>, <a class="txt" href="fintopo6.html#E13:55"><i><font color="Green" title="E38">A9</font></i></a>, <a class="txt" href="fintopo6.html#E1:55_1"><i><font color="Green" title="E39">A10</font></i></a>, <a class="txt" href="fintopo6.html#E3:55_1"><i><font color="Green" title="E41">A12</font></i></a>, <a class="txt" href="fintopo6.html#E9:55_1"><i><font color="Green" title="E46">A17</font></i></a>, <a class="ref" href="fintopo6.html#T33" target="_self" title="FINTOPO6:th.33">Th33</a></i>;<br/></div><b>end;</b></div>
<b>hence </b><a NAME="E15:55"/>
<span class="p1">(<span class="default"><a href="struct_0.html#K2" title="STRUCT_0:func.2">[#]</a> <font color="Maroon" title="c1">FT</font></span>)</span> <a href="subset_1.html#K7" title="SUBSET_1:func.7">\</a> <font color="Maroon" title="c3">C</font> is <a href="fin_topo.html#V5" title="FIN_TOPO:attr.5">connected</a>
 <b>by </b><i><a class="ref" href="fintopo6.html#T7" target="_self" title="FINTOPO6:th.7">Th7</a>, <a class="txt" href="fintopo6.html#E1:55"><i><font color="Green" title="E30">A1</font></i></a></i>;<br/>


</div>
