id	summary	reporter	owner	description	type	status	priority	milestone	component	resolution	keywords	cc	work_issues	upstream	reviewer	author	merged	dependencies	stopgaps
9809	Graph.num_edges() gives wrong answer	tobiasljohnson	somebody	"If G is a graph with multiedges that contains two copies of an edge e, and you delete one of the copies, num_edges() doesn't go down by one.  For example,
{{{
sage: G = Graph(multiedges = True)
sage: G.add_edges([(0,1), (0,1)])
sage: G.delete_edge(0,1)
sage: G.num_edges()
2
sage: G.edges()
[(0, 1, None)]
}}}
"	defect	closed	major	sage-duplicate/invalid/wontfix	graph theory	duplicate	num_edges,multiedges			N/A	Minh Van Nguyen