<?xml version="1.0"?>
<div class="add">

<b>let </b><font color="Maroon">V</font> be   <a href="rlvect_1.html#NM2">RealLinearSpace</a>;<br/><b>let </b><font color="Maroon">W1</font> be    <a href="rlsub_1.html#M1">Subspace</a> of <font color="Maroon">V</font>;<br/><b>let </b><font color="Maroon">W2</font> be    <a href="rlsub_1.html#M1">Subspace</a> of <font color="Maroon">V</font>;<br/><b>let </b><font color="Maroon">W3</font> be    <a href="rlsub_1.html#M1">Subspace</a> of <font color="Maroon">V</font>;<br/>







<b>assume </b><a NAME="E1:30"/><i><font color="Green">E32</font></i>: 
<font color="Maroon">W1</font> is    <a href="rlsub_1.html#M1">Subspace</a> of <font color="Maroon">W2</font>
 ;<br/>

<b>thus </b><a NAME="E2:30"/>
the <a href="struct_0.html#U1">carrier</a> of <span class="p1">(<span class="default"><font color="Maroon">W2</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <span class="p2">(<span class="default"><font color="Maroon">W1</font> <a href="rlsub_2.html#K1" target="_self">+</a> <font color="Maroon">W3</font></span>)</span></span>)</span> <a href="tarski.html#R1">c=</a> the <a href="struct_0.html#U1">carrier</a> of <span class="p1">(<span class="default"><span class="p2">(<span class="default"><font color="Maroon">W1</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <font color="Maroon">W2</font></span>)</span> <a href="rlsub_2.html#K1" target="_self">+</a> <span class="p2">(<span class="default"><font color="Maroon">W2</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <font color="Maroon">W3</font></span>)</span></span>)</span>
  <i><font color="Red">:: according to </font></i><a class="ref" href="xboole_0.html#D10">XBOOLE_0:def 10</a><div><a class="txt" onclick="hs2(this)" href="javascript:()" title="30_1"><b>proof </b></a><div class="add">

<b>let </b><font color="Maroon">x</font> be    <a href="hidden.html#M1">set</a> ; <i><font color="Red">:: according to </font></i><a class="ref" href="tarski.html#D3">TARSKI:def 3</a><br/>

<b>assume </b><a NAME="E1:30_1"/>
<font color="Maroon">x</font> <a href="hidden.html#R2">in</a> the <a href="struct_0.html#U1">carrier</a> of <span class="p1">(<span class="default"><font color="Maroon">W2</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <span class="p2">(<span class="default"><font color="Maroon">W1</font> <a href="rlsub_2.html#K1" target="_self">+</a> <font color="Maroon">W3</font></span>)</span></span>)</span>
 ;<br/>

<a NAME="E2:30_1"/><b>then </b><i><font color="Green">E35</font></i>: 
<font color="Maroon">x</font> <a href="hidden.html#R2">in</a> the <a href="struct_0.html#U1">carrier</a> of <font color="Maroon">W2</font> <a href="xboole_0.html#K3">/\</a> the <a href="struct_0.html#U1">carrier</a> of <span class="p1">(<span class="default"><font color="Maroon">W1</font> <a href="rlsub_2.html#K1" target="_self">+</a> <font color="Maroon">W3</font></span>)</span>
 
<b>by </b><i/>;<br/>
<a NAME="E3:30_1"/><b>then </b>
<font color="Maroon">x</font> <a href="hidden.html#R2">in</a> the <a href="struct_0.html#U1">carrier</a> of <span class="p1">(<span class="default"><font color="Maroon">W1</font> <a href="rlsub_2.html#K1" target="_self">+</a> <font color="Maroon">W3</font></span>)</span>
 
<b>by </b><i><a class="ref" href="xboole_0.html#D3">XBOOLE_0:def 3</a></i>;<br/>
<a NAME="E4:30_1"/><b>then </b>
<font color="Maroon">x</font> <a href="hidden.html#R2">in</a> <span class="p1">{<span class="default"> <span class="p2">(<span class="default"><font color="Olive">u</font> <a href="rlvect_1.html#K4">+</a> <font color="Olive">v</font></span>)</span> where <font color="Olive">u</font> is   <a href="rlvect_1.html#NM1">VECTOR</a> of <font color="Maroon">V</font>, <font color="Olive">v</font> is   <a href="rlvect_1.html#NM1">VECTOR</a> of <font color="Maroon">V</font> : ( <font color="Olive">u</font> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W1</font> &amp; <font color="Olive">v</font> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W3</font> ) </span>}</span> 
 
<b>by </b><i/>;<br/>
<b>then consider </b><font color="Maroon">u1</font> being   <a href="rlvect_1.html#NM1">VECTOR</a> of <font color="Maroon">V</font>, <font color="Maroon">v1</font> being   <a href="rlvect_1.html#NM1">VECTOR</a> of <font color="Maroon">V</font><b> such that </b><br/><a NAME="E6:30_1"/><i><font color="Green">E36</font></i>: 
<font color="Maroon">x</font> <a href="hidden.html#R1">=</a> <font color="Maroon">u1</font> <a href="rlvect_1.html#K4">+</a> <font color="Maroon">v1</font>
 <b>and </b><br/><a NAME="E7:30_1"/><i><font color="Green">E37</font></i>: 
<font color="Maroon">u1</font> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W1</font>
 <b>and </b><br/><a NAME="E8:30_1"/><i><font color="Green">E38</font></i>: 
<font color="Maroon">v1</font> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W3</font>
 ;<br/>
<a NAME="E9:30_1"/><i><font color="Green">E39</font></i>: 
<font color="Maroon">u1</font> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W2</font>
 
<b>by </b><i>, <a class="txt" href="rlsub_2.html#E1:30"><i><font color="Green">E32</font></i></a>, <a class="ref" href="rlsub_1.html#T16">RLSUB_1:16</a></i>;<br/>
<a NAME="E10:30_1"/><b>then </b><i><font color="Green">E56</font></i>: 
<font color="Maroon">u1</font> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W1</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <font color="Maroon">W2</font>
 
<b>by </b><i><a class="txt" href="rlsub_2.html#E1:30"><i><font color="Green">E32</font></i></a>, </i>;<br/>
<a NAME="E11:30_1"/>
<font color="Maroon">x</font> <a href="hidden.html#R2">in</a> the <a href="struct_0.html#U1">carrier</a> of <font color="Maroon">W2</font>
 
<b>by </b><i><a class="ref" href="rlsub_2.html#D1" target="_self">Def1</a>, <a class="ref" href="xboole_0.html#D3">XBOOLE_0:def 3</a></i>;<br/>
<a NAME="E12:30_1"/><b>then </b>
<font color="Maroon">u1</font> <a href="rlvect_1.html#K4">+</a> <font color="Maroon">v1</font> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W2</font>
 
<b>by </b><i>, <a class="ref" href="rlvect_1.html#D1">RLVECT_1:def 1</a></i>;<br/>
<a NAME="E13:30_1"/><b>then </b>
<span class="p1">(<span class="default"><font color="Maroon">v1</font> <a href="rlvect_1.html#K4">+</a> <font color="Maroon">u1</font></span>)</span> <a href="rlvect_1.html#K6">-</a> <font color="Maroon">u1</font> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W2</font>
 
<b>by </b><i>, <a class="ref" href="rlsub_1.html#T31">RLSUB_1:31</a></i>;<br/>
<a NAME="E14:30_1"/><b>then </b>
<font color="Maroon">v1</font> <a href="rlvect_1.html#K4">+</a> <span class="p1">(<span class="default"><font color="Maroon">u1</font> <a href="rlvect_1.html#K6">-</a> <font color="Maroon">u1</font></span>)</span> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W2</font>
 
<b>by </b><i><a class="ref" href="rlvect_1.html#D6">RLVECT_1:def 6</a></i>;<br/>
<a NAME="E15:30_1"/><b>then </b>
<font color="Maroon">v1</font> <a href="rlvect_1.html#K4">+</a> <span class="p1">(<span class="default"><a href="rlvect_1.html#K1">0.</a> <font color="Maroon">V</font></span>)</span> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W2</font>
 
<b>by </b><i><a class="ref" href="rlvect_1.html#T28">RLVECT_1:28</a></i>;<br/>
<a NAME="E16:30_1"/><b>then </b>
<font color="Maroon">v1</font> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W2</font>
 
<b>by </b><i><a class="ref" href="rlvect_1.html#T10">RLVECT_1:10</a></i>;<br/>
<a NAME="E17:30_1"/><b>then </b>
<font color="Maroon">v1</font> <a href="rlvect_1.html#R1">in</a> <font color="Maroon">W2</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <font color="Maroon">W3</font>
 
<b>by </b><i>, </i>;<br/>
<a NAME="E18:30_1"/><b>then </b>
<font color="Maroon">x</font> <a href="rlvect_1.html#R1">in</a> <span class="p1">(<span class="default"><font color="Maroon">W1</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <font color="Maroon">W2</font></span>)</span> <a href="rlsub_2.html#K1" target="_self">+</a> <span class="p1">(<span class="default"><font color="Maroon">W2</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <font color="Maroon">W3</font></span>)</span>
 
<b>by </b><i>, <a class="txt" href="rlsub_2.html#E2:30_1"><i><font color="Green">E35</font></i></a>, </i>;<br/>
<b>hence </b><a NAME="E19:30_1"/>
<font color="Maroon">x</font> <a href="hidden.html#R2">in</a> the <a href="struct_0.html#U1">carrier</a> of <span class="p1">(<span class="default"><span class="p2">(<span class="default"><font color="Maroon">W1</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <font color="Maroon">W2</font></span>)</span> <a href="rlsub_2.html#K1" target="_self">+</a> <span class="p2">(<span class="default"><font color="Maroon">W2</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <font color="Maroon">W3</font></span>)</span></span>)</span>
 <b>by </b><i><a class="ref" href="rlvect_1.html#D1">RLVECT_1:def 1</a></i>;<br/>


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

<b>thus </b><a NAME="E3:30"/>
the <a href="struct_0.html#U1">carrier</a> of <span class="p1">(<span class="default"><span class="p2">(<span class="default"><font color="Maroon">W1</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <font color="Maroon">W2</font></span>)</span> <a href="rlsub_2.html#K1" target="_self">+</a> <span class="p2">(<span class="default"><font color="Maroon">W2</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <font color="Maroon">W3</font></span>)</span></span>)</span> <a href="tarski.html#R1">c=</a> the <a href="struct_0.html#U1">carrier</a> of <span class="p1">(<span class="default"><font color="Maroon">W2</font> <a href="rlsub_2.html#K2" target="_self">/\</a> <span class="p2">(<span class="default"><font color="Maroon">W1</font> <a href="rlsub_2.html#K1" target="_self">+</a> <font color="Maroon">W3</font></span>)</span></span>)</span>
 <b>by </b><i/>;<br/>


</div>
