On the Power of the Weisfeiler-Leman Test for Graph Motif Parameters (2309.17053v3)
Abstract: Seminal research in the field of graph neural networks (GNNs) has revealed a direct correspondence between the expressive capabilities of GNNs and the $k$-dimensional Weisfeiler-Leman ($k$WL) test, a widely-recognized method for verifying graph isomorphism. This connection has reignited interest in comprehending the specific graph properties effectively distinguishable by the $k$WL test. A central focus of research in this field revolves around determining the least dimensionality $k$, for which $k$WL can discern graphs with different number of occurrences of a pattern graph $P$. We refer to such a least $k$ as the WL-dimension of this pattern counting problem. This inquiry traditionally delves into two distinct counting problems related to patterns: subgraph counting and induced subgraph counting. Intriguingly, despite their initial appearance as separate challenges with seemingly divergent approaches, both of these problems are interconnected components of a more comprehensive problem: "graph motif parameters". In this paper, we provide a precise characterization of the WL-dimension of labeled graph motif parameters. As specific instances of this result, we obtain characterizations of the WL-dimension of the subgraph counting and induced subgraph counting problem for every labeled pattern $P$. We additionally demonstrate that in cases where the $k$WL test distinguishes between graphs with varying occurrences of a pattern $P$, the exact number of occurrences of $P$ can be computed uniformly using only local information of the last layer of a corresponding GNN. We finally delve into the challenge of recognizing the WL-dimension of various graph parameters. We give a polynomial time algorithm for determining the WL-dimension of the subgraph counting problem for given pattern $P$, answering an open question from previous work.
- Biomolecular network motif counting and discovery by color coding. Bioinformatics, 13:1–24, 2008.
- On weisfeiler-leman invariance: Subgraph counts and related graph properties. J. Comput. Syst. Sci., 113:42–59, 2020.
- Graph neural networks with local graph parameters. In NeurIPS 2021, pp. 25280–25293, 2021.
- Weisfeiler and leman go relational. In LoG, volume 198 of Proceedings of Machine Learning Research, pp. 46. PMLR, 2022.
- Hans L. Bodlaender. A linear-time algorithm for finding tree-decompositions of small treewidth. SIAM J. Comput., 25(6):1305–1317, 1996. doi: 10.1137/S0097539793251219.
- Improving graph neural network expressivity via subgraph isomorphism counting. IEEE Trans. Pattern Anal. Mach. Intell., 45(1):657–668, 2023.
- Counting graphlets: Space vs time. In WSDM, pp. 557–566. ACM, 2017. doi: 10.1145/3018661.3018732.
- An optimal lower bound on the number of variables for graph identification. Comb., 12(4):389–410, 1992.
- Counting answers to existential positive queries: A complexity classification. In Proc. PODS, pp. 315–326. ACM, 2016. doi: 10.1145/2902251.2902279. URL https://doi.org/10.1145/2902251.2902279.
- Can graph neural networks count substructures? In NeurIPS, 2020.
- Bruno Courcelle. The monadic second-order logic of graphs. i. recognizable sets of finite graphs. Inf. Comput., 85(1):12–75, 1990.
- Homomorphisms are a good basis for counting small subgraphs. In STOC, pp. 210–223. ACM, 2017.
- Learning combinatorial optimization algorithms over graphs. In ICML, 2021.
- Message passing for query answering over knowledge graphs. CoRR, abs/2002.02406, 2020. URL https://arxiv.org/abs/2002.02406.
- Lovász meets weisfeiler and leman. In Proc. ICALP, volume 107 of LIPIcs, pp. 40:1–40:14. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2018. doi: 10.4230/LIPIcs.ICALP.2018.40.
- Counting answers to existential questions. In Proc. ICALP 2019, volume 132 of LIPIcs, pp. 113:1–113:15. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2019.
- Reinhard Diestel. Graph Theory, 4th Edition, volume 173 of Graduate texts in mathematics. Springer, 2012.
- Zdenek Dvorák. On recognizing graphs by numbers of homomorphisms. J. Graph Theory, 64(4):330–342, 2010. doi: 10.1002/jgt.20461.
- A fair comparison of graph neural networks for graph classification. In ICLR, 2020.
- Martin Fürer. On the combinatorial power of the weisfeiler-lehman algorithm. CoRR, abs/1704.01023, 2017. URL http://arxiv.org/abs/1704.01023.
- Inductive logical query answering in knowledge graphs. In NeurIPS, 2022.
- Neural message passing for quantum chemistry. In ICML, 2017.
- The weisfeiler-leman dimension of existential conjunctive queries. 2024.
- Pebble games and linear equations. J. Symb. Log., 80(3):797–844, 2015.
- Knowledge graphs. ACM Comput. Surv., 54(4):71:1–71:37, 2022.
- A theory of link prediction via relational weisfeiler-leman. CoRR, abs/2302.02209, 2023.
- Network global testing by counting graphlets. In ICML, volume 80, pp. 2338–2346. PMLR, 2018. URL http://proceedings.mlr.press/v80/jin18b.html.
- Jakob Jonsson. Simplicial complexes of graphs, volume 3. Springer, 2008.
- A comprehensive survey on graph neural networks. IEEE Communications Surveys & Tutorials, 2020.
- Community detection in graphs with graphsage. In ICLR, 2018. URL https://arxiv.org/abs/1706.02216.
- A property testing framework for the theoretical expressivity of graph kernels. In IJCAI, pp. 2348–2354. ijcai.org, 2018.
- László Lovász. Operations with structures. Acta Mathematica Hungarica, 18(3-4):321–328, 1967.
- Encoding sentences with graph convolutional networks for semantic role labeling. In EMNLP, 2017.
- Weisfeiler and leman go neural: Higher-order graph neural networks. In AAAI, pp. 4602–4609, 2019.
- Weisfeiler and leman go sparse: Towards scalable higher-order graph embeddings. In NeurIPS 2020, 2020.
- Daniel Neuen. Homomorphism-distinguishing closedness for graphs of bounded tree-width. CoRR, abs/2304.07011, 2023.
- OEIS Foundation Inc. The On-Line Encyclopedia of Integer Sequences, 2023. Published electronically at http://oeis.org.
- From local measurements to network spectral properties: Beyond degree distributions. In CDC, pp. 2686–2691. IEEE, 2010.
- David E. Roberson. Oddomorphisms and homomorphism indistinguishability over graphs of bounded degree. CoRR, abs/2206.10321, 2022.
- Graph minors. XX. wagner’s conjecture. J. Comb. Theory, Ser. B, 92(2):325–357, 2004. doi: 10.1016/j.jctb.2004.08.001.
- Marc Roth. Counting problems on quantum graphs: Parameterized and exact complexity classifications, 2019.
- Counting induced subgraphs: A topological approach to #w[1]-hardness. Algorithmica, 82(8):2267–2291, 2020.
- Modeling relational data with graph convolutional networks. In ESWC, 2018.
- Tim Seppelt. Logical equivalences, homomorphism indistinguishability, and forbidden minors. CoRR, abs/2302.11290, 2023.
- Efficient graphlet kernels for large graph comparison. In AISTATS, volume 5 of JMLR Proceedings, 2009.
- Inductive relation prediction by subgraph reasoning. In ICML, pp. 9448–9457, 2020.
- The reduction of a graph to canonical form and the algebra which appears therein, 1968.
- A comprehensive survey on graph neural networks. IEEE Transactions on Neural Networks and Learning Systems, 2021.
- Graph neural networks in node classification: survey and evaluation. Mach. Vis. Appl., 33(1):4, 2022.
- How powerful are graph neural networks? In ICLR, 2019.
- Graph convolutional neural networks for web-scale recommender systems. In KDD, 2018.
- Graph neural networks: A review of methods and applications. AI Open, 2020.
- Neural bellman-ford networks: A general graph neural network framework for link prediction. In NeurIPS 2021, pp. 29476–29490, 2021.