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,,,,