Two other graph functions work with graphs that are not necessarily 4-valent. The function fKLinGraph (webMathematica fKLinGraph) gives all non-isomorphic KL projections contained in a given graph G. For example, the graph 
{{1,2},{1,2},{1,4},{1,4},{1,5},{2,3},{2,3},{2,5},{3,4},{3,4},{3,5},{4,5}}

contains two KL graphs: the graph 

{{1,2},{1,2},{1,4},{1,4},{2,3},{2,3},{3,4},{3,4}}

corresponding to a link 412 (4) and the graph 

{{1,2},{1,2},{1,4},{1,5},{2,3},{2,5},{3,4},{3,4},{3,5},{4,5}}

corresponding to the Whitehead link 512 (2 1 2) (b). The function fAddDig (webMathematica fAddDig) produces from a given graph G all 4-regular non-isomorphic graphs by replacing single edges by double (bigonal) edges. For example, from the 3-valent graph  

{{1,2},{1,3},{1,6},{2,4},{2,6},{3,4},{3,5},{4,5},{5,6}}

we obtain two non-isomorphic 4-valent graphs

{{1,2},{1,2},{1,3},{1,6},{2,4},{2,6},{3,4},{3,4},{3,5},{4,5},{5,6},{5,6}}
and 
{{1,2},{1,3},{1,3},{1,6},{2,4},{2,4},{2,6},{3,4},{3,5},{4,5},{5,6},{5,6}}.


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