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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="altcat_1.html#NM4">category</a>;<br/><b>let </b><font color="Maroon">c<sub>3</sub></font>, <font color="Maroon">c<sub>4</sub></font> be  <a href="functor0.html#V15">covariant</a>  <a href="functor0.html#M2">Functor</a> of <font color="Maroon">c<sub>2</sub></font>,<font color="Maroon">c<sub>1</sub></font>;<br/><b>let </b><font color="Maroon">c<sub>5</sub></font> be    <a href="functor3.html#M1" target="_self">natural_equivalence</a> of <font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font>;<br/><b>let </b><font color="Maroon">c<sub>6</sub></font> be   <a href="altcat_1.html#NM1">object</a> of <font color="Maroon">c<sub>2</sub></font>;<br/>











<b>assume </b><a NAME="E1:57"/><i><font color="Green">E33</font></i>: 
<font color="Maroon">c<sub>3</sub></font>,<font color="Maroon">c<sub>4</sub></font> <a href="functor3.html#R1" target="_self">are_naturally_equivalent</a> 
 ;<br/>

<a NAME="E2:57"/><b>then </b>
<font color="Maroon">c<sub>4</sub></font> <a href="functor2.html#R1">is_transformable_to</a> <font color="Maroon">c<sub>3</sub></font>
 
<b>by </b><i><a class="ref" href="functor3.html#D4" target="_self">Def4</a></i>;<br/>
<b>hence </b><span class="p1">(<span class="default"><font color="Maroon">c<sub>5</sub></font> <a href="functor3.html#K8" target="_self">"</a> </span>)</span> <a href="functor2.html#K2">!</a> <font color="Maroon">c<sub>6</sub></font> = 
<span class="p1">(<span class="default"><font color="Maroon">c<sub>5</sub></font> <a href="functor3.html#K8" target="_self">"</a> </span>)</span> <a href="funct_1.html#K1">.</a> <font color="Maroon">c<sub>6</sub></font>
<b>by </b><i><a class="ref" href="functor2.html#D4">FUNCTOR2:def 4</a></i>
<br/>.= 
<span class="p1">(<span class="default"><font color="Maroon">c<sub>5</sub></font> <a href="functor2.html#K2">!</a> <font color="Maroon">c<sub>6</sub></font></span>)</span> <a href="altcat_3.html#K1">"</a> 
<b>by </b><i><a class="txt" href="functor3.html#E1:57"><i><font color="Green">E33</font></i></a>, <a class="ref" href="functor3.html#D6" target="_self">Def6</a></i>
;<br/><br/>


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