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<b>set </b><font color="Maroon" title="c3">Y</font> =  <a href="roughs_1.html#K4" title="ROUGHS_1:func.4">UAp</a> <font color="Maroon" title="c2">X</font>;<br/>
<a NAME="E1:61_2_1"/>
 <a href="roughs_1.html#K4" title="ROUGHS_1:func.4">UAp</a> <span class="p1">(<span class="default"><a href="roughs_1.html#K4" title="ROUGHS_1:func.4">UAp</a> <font color="Maroon" title="c2">X</font></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="roughs_1.html#K3" title="ROUGHS_1:func.3">LAp</a> <span class="p1">(<span class="default"><a href="roughs_1.html#K4" title="ROUGHS_1:func.4">UAp</a> <font color="Maroon" title="c2">X</font></span>)</span>
 
<b>by </b><i><a class="ref" href="roughs_1.html#T36" target="_self" title="ROUGHS_1:th.36">Th36</a></i>;<br/>
<a NAME="E2:61_2_1"/><b>then </b>
<span class="p1">(<span class="default"><a href="roughs_1.html#K4" title="ROUGHS_1:func.4">UAp</a> <span class="p2">(<span class="default"><a href="roughs_1.html#K4" title="ROUGHS_1:func.4">UAp</a> <font color="Maroon" title="c2">X</font></span>)</span></span>)</span> <a href="subset_1.html#K7" title="SUBSET_1:func.7">\</a> <span class="p1">(<span class="default"><a href="roughs_1.html#K3" title="ROUGHS_1:func.3">LAp</a> <span class="p2">(<span class="default"><a href="roughs_1.html#K4" title="ROUGHS_1:func.4">UAp</a> <font color="Maroon" title="c2">X</font></span>)</span></span>)</span> <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_1.html#T37" title="XBOOLE_1:th.37">XBOOLE_1:37</a></i>;<br/>
<a NAME="E3:61_2_1"/><b>then </b>
 <a href="roughs_1.html#K5" title="ROUGHS_1:func.5">BndAp</a> <span class="p1">(<span class="default"><a href="roughs_1.html#K4" title="ROUGHS_1:func.4">UAp</a> <font color="Maroon" title="c2">X</font></span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
 
;<br/>
<b>hence </b><a NAME="E4:61_2_1"/>
not  <a href="roughs_1.html#K4" title="ROUGHS_1:func.4">UAp</a> <font color="Maroon" title="c2">X</font> is <a href="roughs_1.html#V4" title="ROUGHS_1:attr.4">rough</a>
 <b>by </b><i><a class="ref" href="roughs_1.html#D7" target="_self" title="ROUGHS_1:def.7">Def7</a></i>;<br/>


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