In the first case, the set of edges among users U in the similarity graph G consists of the logical OR between the 2-hop closure of the U2H and the U2M graph.
for each two users u, v ∈ U , there is an edge in the similarity graph (u, v) ∈ E if u and v share a common hashtag or a common user mention The graph therefore uses the same information that is available to the embeddings.