Other vertex and edge sequence operations:
c.igraph.es(),
c.igraph.vs(),
difference.igraph.es(),
igraph-es-indexing2,
igraph-es-indexing,
igraph-vs-indexing2,
igraph-vs-indexing,
intersection.igraph.es(),
intersection.igraph.vs(),
rev.igraph.es(),
rev.igraph.vs(),
union.igraph.es(),
union.igraph.vs(),
unique.igraph.es(),
unique.igraph.vs()