<p>The Borromean rings -- no two circles are directly linked, but the three are collectively interlinked.  Cutting one ring frees the other two.  In terms of knot theory, a <a href="//commons.wikimedia.org/wiki/File:Brunnian-4loops.svg" title="File:Brunnian-4loops.svg">"Brunnian link"</a>.
</p><p>For a monochrome version of this graphic, see <a href="//commons.wikimedia.org/wiki/File:Borromean-rings-BW.svg" title="File:Borromean-rings-BW.svg">File:Borromean-rings-BW.svg</a> .
</p><p>For a version of the Borromean rings depicted in triangular form, see <a href="//commons.wikimedia.org/wiki/File:Valknut-Symbol-borromean.svg" title="File:Valknut-Symbol-borromean.svg">Image:Valknut-Symbol-borromean.svg</a> .
</p><p>For extended Borromean patterns, see <a href="//commons.wikimedia.org/wiki/File:Borromean-cross.png" title="File:Borromean-cross.png">Image:Borromean-cross.png</a> / <a href="//commons.wikimedia.org/wiki/File:Borromean-cross.svg" title="File:Borromean-cross.svg">Image:Borromean-cross.svg</a> and <a href="//commons.wikimedia.org/wiki/File:Borromean-chainmail-tile.png" title="File:Borromean-chainmail-tile.png">Image:Borromean-chainmail-tile.png</a> .
</p><p>For other (more complex) three-component Brunnian links which are <i>not</i> equivalent to the Borromean rings, see <a href="//commons.wikimedia.org/wiki/File:Brunnian-3-not-Borromean.png" title="File:Brunnian-3-not-Borromean.png">Image:Brunnian-3-not-Borromean.png</a> and <a href="//commons.wikimedia.org/wiki/File:Three-triang-18crossings-Brunnian.png" title="File:Three-triang-18crossings-Brunnian.png">Image:Three-triang-18crossings-Brunnian.png</a> .
</p>
SVG version of <a href="//commons.wikimedia.org/wiki/File:Borromeanrings.png" title="File:Borromeanrings.png">Image:Borromeanrings.png</a> .
AnonMoos
<p>Converted from the following PostScript code:
</p>
<pre>%!
77 110 translate
.75 dup scale
/y{240 120 3 sqrt mul add}def
20 setlinewidth
426 y 240 0 360 arc
closepath gsave
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186 y 240 0 360 arc
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stroke
306 240 240 0 360 arc
closepath gsave
30 setlinewidth
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grestore
1 0 0 setrgbcolor
stroke
30 setlinewidth
0 setgray
426 y 240 -65 -55 arc stroke
426 y 240 175 185 arc stroke
20 setlinewidth
0 0 1 setrgbcolor
426 y 240 -66 -54 arc stroke
426 y 240 174 186 arc stroke
%EOF</pre>