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<b>let </b><font color="Maroon" title="c1">C</font>, <font color="Maroon" title="c2">D</font> be   <a href="cat_1.html#NM4" title="CAT_1:NM.4">Category</a>;<br/><b>let </b><font color="Maroon" title="c3">T</font> be    <a href="cat_1.html#M2" title="CAT_1:mode.2">Functor</a> of <font color="Maroon" title="c1">C</font>,<font color="Maroon" title="c2">D</font>;<br/>





<b>thus </b><a NAME="E1:113"/>
( <font color="Maroon" title="c3">T</font> is <a href="cat_1.html#V11" title="CAT_1:attr.11">faithful</a> implies for <font color="Olive" title="b1">c</font>, <font color="Olive" title="b2">c'</font> being  <a href="cat_1.html#NM1" title="CAT_1:NM.1">Object</a> of <font color="Maroon" title="c1">C</font> holds   <a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Olive" title="b1">c</font>,<font color="Olive" title="b2">c'</font> is <a href="funct_1.html#V2" title="FUNCT_1:attr.2">one-to-one</a> )
 <div><a class="txt" onclick="hs2(this)" href="javascript:()" title="113_1"><b>proof </b></a><div class="add">

<b>assume </b><a NAME="E1:113_1"/><i><font color="Green" title="E62">A1</font></i>: 
<font color="Maroon" title="c3">T</font> is <a href="cat_1.html#V11" title="CAT_1:attr.11">faithful</a>
 ;<br/>

<b>let </b><font color="Maroon" title="c4">c</font>, <font color="Maroon" title="c5">c'</font> be   <a href="cat_1.html#NM1" title="CAT_1:NM.1">Object</a> of <font color="Maroon" title="c1">C</font>;<br/>

<div><i><font color="Green" title="E63">A2</font></i>: <a class="txt" onclick="hs2(this)" href="javascript:()" title="113_1_1"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:113_1_1"/>
 <a href="cat_1.html#K7" title="CAT_1:func.7">Hom</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">T</font> <a href="cat_1.html#K13" title="CAT_1:func.13">.</a> <font color="Maroon" title="c4">c</font></span>)</span>,<span class="p1">(<span class="default"><font color="Maroon" title="c3">T</font> <a href="cat_1.html#K13" title="CAT_1:func.13">.</a> <font color="Maroon" title="c5">c'</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/><a NAME="E2:113_1_1"/><b>then </b>
 <a href="cat_1.html#K7" title="CAT_1:func.7">Hom</a> <font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> <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="cat_1.html#T126" target="_self" title="CAT_1:th.126">Th126</a></i>;<br/><b>hence </b><a NAME="E3:113_1_1"/>
 <a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> is <a href="funct_1.html#V2" title="FUNCT_1:attr.2">one-to-one</a>
 <b>by </b><i><a class="ref" href="partfun1.html#T59" title="PARTFUN1:th.59">PARTFUN1:59</a></i>;<br/></div><b>end;</b></div>
<div><a class="txt" onclick="hs2(this)" href="javascript:()" title="113_1_2"><b>now </b></a><div class="add"><b>assume </b><a NAME="E1:113_1_2"/><i><font color="Green" title="E64">A3</font></i>: 
 <a href="cat_1.html#K7" title="CAT_1:func.7">Hom</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">T</font> <a href="cat_1.html#K13" title="CAT_1:func.13">.</a> <font color="Maroon" title="c4">c</font></span>)</span>,<span class="p1">(<span class="default"><font color="Maroon" title="c3">T</font> <a href="cat_1.html#K13" title="CAT_1:func.13">.</a> <font color="Maroon" title="c5">c'</font></span>)</span> <a href="hidden.html#NR2" title="HIDDEN:NR.2">&lt;&gt;</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
 ;<br/><div><a class="txt" onclick="hs2(this)" href="javascript:()" title="113_1_2_1"><b>now </b></a><div class="add"><b>let </b><font color="Maroon" title="c6">f1</font>, <font color="Maroon" title="c7">f2</font> be    <a href="hidden.html#M1" title="HIDDEN:mode.1">set</a> ;<br/><b>assume </b><a NAME="E1:113_1_2_1"/>
( <font color="Maroon" title="c6">f1</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="cat_1.html#K7" title="CAT_1:func.7">Hom</a> <font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> &amp; <font color="Maroon" title="c7">f2</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="cat_1.html#K7" title="CAT_1:func.7">Hom</a> <font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> )
 ;<br/><a NAME="E2:113_1_2_1"/><b>then </b><i><font color="Green" title="E65">A4</font></i>: 
( <font color="Maroon" title="c6">f1</font> is    <a href="cat_1.html#M1" title="CAT_1:mode.1">Morphism</a> of <font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> &amp; <font color="Maroon" title="c7">f2</font> is    <a href="cat_1.html#M1" title="CAT_1:mode.1">Morphism</a> of <font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> &amp;  <a href="cat_1.html#K7" title="CAT_1:func.7">Hom</a> <font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> <a href="hidden.html#NR2" title="HIDDEN:NR.2">&lt;&gt;</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  )
 <b>by </b><i><a class="ref" href="cat_1.html#D7" target="_self" title="CAT_1:def.7">Def7</a></i>;<br/><a NAME="E3:113_1_2_1"/><b>then </b>
( <font color="Maroon" title="c3">T</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <font color="Maroon" title="c6">f1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1">(<span class="default"><a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font></span>)</span> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <font color="Maroon" title="c6">f1</font> &amp; <font color="Maroon" title="c3">T</font> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <font color="Maroon" title="c7">f2</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1">(<span class="default"><a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font></span>)</span> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <font color="Maroon" title="c7">f2</font> )
 <b>by </b><i><a class="ref" href="cat_1.html#T131" target="_self" title="CAT_1:th.131">Th131</a></i>;<br/><b>hence </b><a NAME="E4:113_1_2_1"/>
( <span class="p1">(<span class="default"><a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font></span>)</span> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <font color="Maroon" title="c6">f1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1">(<span class="default"><a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font></span>)</span> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <font color="Maroon" title="c7">f2</font> implies <font color="Maroon" title="c6">f1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c7">f2</font> )
 <b>by </b><i><a class="txt" href="cat_1.html#E1:113_1"><i><font color="Green" title="E62">A1</font></i></a>, <a class="txt" href="cat_1.html#E2:113_1_2_1"><i><font color="Green" title="E65">A4</font></i></a>, <a class="ref" href="cat_1.html#D24" target="_self" title="CAT_1:def.24">Def24</a></i>;<br/></div><b>end;</b></div><b>hence </b><a NAME="E3:113_1_2"/>
 <a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> is <a href="funct_1.html#V2" title="FUNCT_1:attr.2">one-to-one</a>
 <b>by </b><i><a class="txt" href="cat_1.html#E1:113_1_2"><i><font color="Green" title="E64">A3</font></i></a>, <a class="ref" href="funct_2.html#T25" title="FUNCT_2:th.25">FUNCT_2:25</a></i>;<br/></div><b>end;</b></div>
<b>hence </b><a NAME="E4:113_1"/>
 <a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> is <a href="funct_1.html#V2" title="FUNCT_1:attr.2">one-to-one</a>
 <b>by </b><i><a class="txt" href="cat_1.html#E2:113_1"><i><font color="Green" title="E63">A2</font></i></a></i>;<br/>


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

<b>assume </b><a NAME="E2:113"/><i><font color="Green" title="E62">A5</font></i>: 
for <font color="Olive" title="b1">c</font>, <font color="Olive" title="b2">c'</font> being  <a href="cat_1.html#NM1" title="CAT_1:NM.1">Object</a> of <font color="Maroon" title="c1">C</font> holds   <a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Olive" title="b1">c</font>,<font color="Olive" title="b2">c'</font> is <a href="funct_1.html#V2" title="FUNCT_1:attr.2">one-to-one</a>
 ;<br/>

<b>let </b><font color="Maroon" title="c4">c</font>, <font color="Maroon" title="c5">c'</font> be   <a href="cat_1.html#NM1" title="CAT_1:NM.1">Object</a> of <font color="Maroon" title="c1">C</font>; <i><font color="Red">:: according to </font></i><a class="ref" href="cat_1.html#D24" target="_self" title="CAT_1:def.24">CAT_1:def 24</a><br/>

<b>assume </b><a NAME="E3:113"/><i><font color="Green" title="E63">A6</font></i>: 
 <a href="cat_1.html#K7" title="CAT_1:func.7">Hom</a> <font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> <a href="hidden.html#NR2" title="HIDDEN:NR.2">&lt;&gt;</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a> 
 ;<br/>

<b>let </b><font color="Maroon" title="c6">f1</font>, <font color="Maroon" title="c7">f2</font> be    <a href="cat_1.html#M1" title="CAT_1:mode.1">Morphism</a> of <font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font>;<br/>

<a NAME="E4:113"/>
(  <a href="cat_1.html#K7" title="CAT_1:func.7">Hom</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">T</font> <a href="cat_1.html#K13" title="CAT_1:func.13">.</a> <font color="Maroon" title="c4">c</font></span>)</span>,<span class="p1">(<span class="default"><font color="Maroon" title="c3">T</font> <a href="cat_1.html#K13" title="CAT_1:func.13">.</a> <font color="Maroon" title="c5">c'</font></span>)</span> <a href="hidden.html#NR2" title="HIDDEN:NR.2">&lt;&gt;</a>  <a href="xboole_0.html#K1" title="XBOOLE_0:func.1">{}</a>  &amp; <font color="Maroon" title="c6">f1</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="cat_1.html#K7" title="CAT_1:func.7">Hom</a> <font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> &amp; <font color="Maroon" title="c7">f2</font> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="cat_1.html#K7" title="CAT_1:func.7">Hom</a> <font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> &amp;  <a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font> is <a href="funct_1.html#V2" title="FUNCT_1:attr.2">one-to-one</a> &amp; <font color="Maroon" title="c3">T</font> <a href="funct_2.html#K3" title="FUNCT_2:func.3">.</a> <font color="Maroon" title="c6">f1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1">(<span class="default"><a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font></span>)</span> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <font color="Maroon" title="c6">f1</font> &amp; <font color="Maroon" title="c3">T</font> <a href="funct_2.html#K3" title="FUNCT_2:func.3">.</a> <font color="Maroon" title="c7">f2</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1">(<span class="default"><a href="cat_1.html#K16" title="CAT_1:func.16">hom</a> <font color="Maroon" title="c3">T</font>,<font color="Maroon" title="c4">c</font>,<font color="Maroon" title="c5">c'</font></span>)</span> <a href="funct_1.html#K1" title="FUNCT_1:func.1">.</a> <font color="Maroon" title="c7">f2</font> )
 
<b>by </b><i><a class="txt" href="cat_1.html#E2:113"><i><font color="Green" title="E62">A5</font></i></a>, <a class="txt" href="cat_1.html#E3:113"><i><font color="Green" title="E63">A6</font></i></a>, <a class="ref" href="cat_1.html#D7" target="_self" title="CAT_1:def.7">Def7</a>, <a class="ref" href="cat_1.html#T126" target="_self" title="CAT_1:th.126">Th126</a>, <a class="ref" href="cat_1.html#T131" target="_self" title="CAT_1:th.131">Th131</a></i>;<br/>
<b>hence </b><a NAME="E5:113"/>
( <font color="Maroon" title="c3">T</font> <a href="funct_2.html#K3" title="FUNCT_2:func.3">.</a> <font color="Maroon" title="c6">f1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c3">T</font> <a href="funct_2.html#K3" title="FUNCT_2:func.3">.</a> <font color="Maroon" title="c7">f2</font> implies <font color="Maroon" title="c6">f1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c7">f2</font> )
 <b>by </b><i><a class="ref" href="funct_2.html#T25" title="FUNCT_2:th.25">FUNCT_2:25</a></i>;<br/>


</div>
