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<b>let </b><font color="Maroon">c<sub>1</sub></font> be  <a href="yellow_0.html#V1">lower-bounded</a> <a href="waybel_0.html#NM8">LATTICE</a>;<br/>

<b>thus </b><a NAME="E1:23"/>
( <font color="Maroon">c<sub>1</sub></font> is <a href="waybel_3.html#V3">continuous</a> implies ex <font color="Olive">b<sub>1</sub></font> being non <a href="xboole_0.html#V1">empty</a>  <a href="hidden.html#M1">set</a> ex <font color="Olive">b<sub>2</sub></font> being <a href="waybel_1.html#V6">projection</a> <a href="struct_0.html#NM7">Function</a> of <span class="p1">(<span class="default"><a href="yellow_1.html#K3">BoolePoset</a> <font color="Olive">b<sub>1</sub></font></span>)</span>,<span class="p1">(<span class="default"><a href="yellow_1.html#K3">BoolePoset</a> <font color="Olive">b<sub>1</sub></font></span>)</span> st <br/>( <font color="Olive">b<sub>2</sub></font> is <a href="waybel_0.html#V22">directed-sups-preserving</a> &amp; <font color="Maroon">c<sub>1</sub></font>, <a href="yellow_2.html#K1">Image</a> <font color="Olive">b<sub>2</sub></font> <a href="waybel_1.html#R5">are_isomorphic</a>  ) )
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="23_1"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:23_1"/>
<font color="Maroon">c<sub>1</sub></font> is <a href="waybel_3.html#V3">continuous</a>
 ;<br/>

<a NAME="E2:23_1"/><b>then </b>
ex <font color="Olive">b<sub>1</sub></font> being <a href="yellow_0.html#V1">lower-bounded</a> <a href="waybel_8.html#V3">arithmetic</a> <a href="waybel_0.html#NM8">LATTICE</a>ex <font color="Olive">b<sub>2</sub></font> being  <a href="struct_0.html#NM7">Function</a> of <font color="Olive">b<sub>1</sub></font>,<font color="Maroon">c<sub>1</sub></font> st <br/>( <font color="Olive">b<sub>2</sub></font> is <a href="funct_2.html#V2">onto</a> &amp; <font color="Olive">b<sub>2</sub></font> is <a href="waybel_0.html#V17">infs-preserving</a> &amp; <font color="Olive">b<sub>2</sub></font> is <a href="waybel_0.html#V22">directed-sups-preserving</a> )
 
<b>by </b><i><a class="txt" href="waybel15.html#E14"><i><font color="Green">Lemma12</font></i></a></i>;<br/>
<b>hence </b><a NAME="E3:23_1"/>
ex <font color="Olive">b<sub>1</sub></font> being non <a href="xboole_0.html#V1">empty</a>  <a href="hidden.html#M1">set</a> ex <font color="Olive">b<sub>2</sub></font> being <a href="waybel_1.html#V6">projection</a> <a href="struct_0.html#NM7">Function</a> of <span class="p1">(<span class="default"><a href="yellow_1.html#K3">BoolePoset</a> <font color="Olive">b<sub>1</sub></font></span>)</span>,<span class="p1">(<span class="default"><a href="yellow_1.html#K3">BoolePoset</a> <font color="Olive">b<sub>1</sub></font></span>)</span> st <br/>( <font color="Olive">b<sub>2</sub></font> is <a href="waybel_0.html#V22">directed-sups-preserving</a> &amp; <font color="Maroon">c<sub>1</sub></font>, <a href="yellow_2.html#K1">Image</a> <font color="Olive">b<sub>2</sub></font> <a href="waybel_1.html#R5">are_isomorphic</a>  )
 <b>by </b><i><a class="txt" href="waybel15.html#E18"><i><font color="Green">Lemma16</font></i></a></i>;<br/>


</div><b>end;</b></div>

<b>thus </b><a NAME="E2:23"/>
( ex <font color="Olive">b<sub>1</sub></font> being   <a href="hidden.html#M1">set</a> ex <font color="Olive">b<sub>2</sub></font> being <a href="waybel_1.html#V6">projection</a> <a href="struct_0.html#NM7">Function</a> of <span class="p1">(<span class="default"><a href="yellow_1.html#K3">BoolePoset</a> <font color="Olive">b<sub>1</sub></font></span>)</span>,<span class="p1">(<span class="default"><a href="yellow_1.html#K3">BoolePoset</a> <font color="Olive">b<sub>1</sub></font></span>)</span> st <br/>( <font color="Olive">b<sub>2</sub></font> is <a href="waybel_0.html#V22">directed-sups-preserving</a> &amp; <font color="Maroon">c<sub>1</sub></font>, <a href="yellow_2.html#K1">Image</a> <font color="Olive">b<sub>2</sub></font> <a href="waybel_1.html#R5">are_isomorphic</a>  ) implies <font color="Maroon">c<sub>1</sub></font> is <a href="waybel_3.html#V3">continuous</a> )
 <b>by </b><i><a class="txt" href="waybel15.html#E21"><i><font color="Green">Lemma19</font></i></a></i>;<br/>


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