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<b>let </b><font color="Maroon">c<sub>1</sub></font>, <font color="Maroon">c<sub>2</sub></font> be    <a href="hidden.html#M1">set</a> ;<br/>



<a NAME="E1:8"/>
(  <a href="gate_1.html#NR1" target="_self">$</a>  <a href="gate_1.html#K5" target="_self">EQV2</a> <font color="Maroon">c<sub>1</sub></font>,<font color="Maroon">c<sub>2</sub></font> iff (  <a href="gate_1.html#NR1" target="_self">$</a> <font color="Maroon">c<sub>1</sub></font> iff  <a href="gate_1.html#NR1" target="_self">$</a> <font color="Maroon">c<sub>2</sub></font> ) )
 
<b>by </b><i><a class="ref" href="gate_1.html#D5" target="_self">Def5</a>, <a class="ref" href="gate_1.html#T5" target="_self">Th5</a></i>;<br/>
<b>hence </b><a NAME="E2:8"/>
(  <a href="gate_1.html#NR1" target="_self">$</a>  <a href="gate_1.html#K5" target="_self">EQV2</a> <font color="Maroon">c<sub>1</sub></font>,<font color="Maroon">c<sub>2</sub></font> iff not  <a href="gate_1.html#NR1" target="_self">$</a>  <a href="gate_1.html#K4" target="_self">XOR2</a> <font color="Maroon">c<sub>1</sub></font>,<font color="Maroon">c<sub>2</sub></font> )
 <b>by </b><i><a class="ref" href="gate_1.html#D4" target="_self">Def4</a>, <a class="ref" href="gate_1.html#T5" target="_self">Th5</a></i>;<br/>


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