1) list(graphs.nauty_geng(0)) gives empty list, whereas Sage knows a graph
of 0 vertices. Can someone ask McKay to handle this special case too?
2) Is there an example of graph property that holds after deleting any
vertex but not necessarily after deleting an edge? Or the converse?
3) Currently graphs(...) has parameters vertices and augment. With
graphs(n, augment='edges') it generates all n-vertex graphs, whereas
graphs(n, augment='vertices') generates all graphs of 0, 1, ..., n
vertices. Would it be more logical to have parameters max_vertices and
min_vertices?
4) When is augment='edges' usefull? Is
sum(sum(1 for _ in graphs(i, augment='edges')) for i in range(9))
faster in someone's computer than
sum(1 for _ in graphs(8, augment='vertices'))
?
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Jori Mäntysalo
