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and vertex
degrees 
for 
,
..., 
is defined by
(e.g., Lin et al. 2023) and 
(e.g., Devillers and Balaban 2000) are variously used.
(defined by Platt) and 
(defined by Gordon and Scantlebury) by
is the edge count of a graph 
(Devillers and Balaban p. 27, 2000).
