Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Notation used in this paper
| Symbol | Definition |
|---|---|
| G(V, E) | A labeled graph with node set V and edge set E |
| L | Set of node labels |
| φ () | Function mapping nodes to labels |
| w () | Function mapping edges to weights |
| Q (VQ, EQ) | Tree pattern with node set VQ and edge set EQ |
| ψ () | Required labels for a graph node matched to a query node |
| ⊥(Q) | Set of leaf nodes (or terminals) in Q |
| ⊤(Q) | Chosen root node in Q |
| N(v, ℓ) | Set of neighbors of v in G with label ℓ |
| λ () | Function mapping query nodes VQ to graph nodes V |
