<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
 "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<!-- Generated by graphviz version 2.38.0 (20140413.2041)
 -->
<!-- Title: G Pages: 1 -->
<svg width="134pt" height="116pt"
 viewBox="0.00 0.00 134.00 116.00" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g id="graph0" class="graph" transform="scale(1 1) rotate(0) translate(4 112)">
<title>G</title>
<polygon fill="white" stroke="none" points="-4,4 -4,-112 130,-112 130,4 -4,4"/>
<!-- ab -->
<g id="node1" class="node"><title>ab</title>
<ellipse fill="none" stroke="black" cx="27" cy="-90" rx="27" ry="18"/>
<text text-anchor="middle" x="27" y="-86.3" font-family="Times,serif" font-size="14.00">ab</text>
</g>
<!-- cd -->
<g id="node2" class="node"><title>cd</title>
<ellipse fill="none" stroke="black" cx="27" cy="-18" rx="27" ry="18"/>
<text text-anchor="middle" x="27" y="-14.3" font-family="Times,serif" font-size="14.00">cd</text>
</g>
<!-- ab&#45;&gt;cd -->
<g id="edge1" class="edge"><title>ab&#45;&gt;cd</title>
<path fill="none" stroke="black" d="M27,-71.6966C27,-63.9827 27,-54.7125 27,-46.1124"/>
<polygon fill="black" stroke="black" points="30.5001,-46.1043 27,-36.1043 23.5001,-46.1044 30.5001,-46.1043"/>
</g>
<!-- CD -->
<g id="node3" class="node"><title>CD</title>
<ellipse fill="none" stroke="black" cx="99" cy="-18" rx="27" ry="18"/>
<text text-anchor="middle" x="99" y="-14.3" font-family="Times,serif" font-size="14.00">CD</text>
</g>
<!-- ab&#45;&gt;CD -->
<g id="edge2" class="edge"><title>ab&#45;&gt;CD</title>
<path fill="none" stroke="black" d="M27,-89C27,-89 55.8659,-60.9359 77.0432,-40.3469"/>
<polygon fill="black" stroke="black" points="79.6995,-42.6458 84.4297,-33.1655 74.82,-37.6269 79.6995,-42.6458"/>
</g>
<!-- AB -->
<g id="node4" class="node"><title>AB</title>
<ellipse fill="none" stroke="black" cx="99" cy="-90" rx="27" ry="18"/>
<text text-anchor="middle" x="99" y="-86.3" font-family="Times,serif" font-size="14.00">AB</text>
</g>
<!-- AB&#45;&gt;cd -->
<g id="edge4" class="edge"><title>AB&#45;&gt;cd</title>
<path fill="none" stroke="black" d="M99,-89C99,-89 52.83,-44.1125 34.4341,-26.2276"/>
<polygon fill="black" stroke="black" points="36.6098,-23.4613 27,-19 31.7302,-28.4803 36.6098,-23.4613"/>
</g>
<!-- AB&#45;&gt;CD -->
<g id="edge3" class="edge"><title>AB&#45;&gt;CD</title>
<path fill="none" stroke="black" d="M99,-71.6966C99,-58.4171 99,-40.5253 99,-29.3805"/>
<polygon fill="black" stroke="black" points="102.5,-29 99,-19 95.5001,-29 102.5,-29"/>
</g>
</g>
</svg>