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Adumbrativus (talk | contribs) Linkify Heawood graph |
Added gallery with images of embeddings of Petersen, Pappus and Klein graphs. |
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An embedding of a graph into three-dimensional space in which no two of the cycles are topologically linked is called a [[linkless embedding]]. A graph has a linkless embedding if and only if it does not have one of the seven graphs of the [[Petersen family]] as a [[minor (graph theory)|minor]].
==Gallery==
<gallery>
File:Petersen-graph.png|thumb|The [[Petersen graph]] and associated map embedded in the projective plane. Opposite points on the circle are identified yielding a closed surface of non-orientable genus 1.
File:Pappus-graph-on-torus.png|The [[Pappus graph]] and associated map embedded in the torus.
File:Klein-map.png|thumb|The degree 7 [[Klein graph]] and associated map embedded in an orientable surface of genus 3.
</gallery>
==See also==
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