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<b>let </b><font color="Maroon">p</font> be  <a href="xboolean.html#V1" target="_self">boolean</a>  <a href="ordinal1.html#NM1" target="_self">number</a> ;<br/><b>let </b><font color="Maroon">q</font> be  <a href="xboolean.html#V1" target="_self">boolean</a>  <a href="ordinal1.html#NM1" target="_self">number</a> ;<br/>



<a NAME="E1:97"/>
( <font color="Maroon">p</font> <a href="hidden.html#R1">=</a>  <a href="xboolean.html#K1" target="_self">FALSE</a>  or <font color="Maroon">p</font> <a href="hidden.html#R1">=</a>  <a href="xboolean.html#K2" target="_self">TRUE</a>  )
 
<b>by </b><i/>;<br/>
<b>hence </b><a NAME="E2:97"/>
<font color="Maroon">p</font> <a href="xboolean.html#K10" target="_self">'xor'</a> <span class="p1">(<span class="default"><font color="Maroon">p</font> <a href="xboolean.html#K9" target="_self">'nor'</a> <font color="Maroon">q</font></span>)</span> <a href="hidden.html#R1">=</a> <font color="Maroon">q</font> <a href="xboolean.html#K6" target="_self">=&gt;</a> <font color="Maroon">p</font>
 ;<br/>


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