Neurosymbolic AI
Overview
Neurosymbolic AI combines the pattern-recognition power of neural networks with the rigour of symbolic reasoning. My work in this area focuses on formally verifying correctness and robustness properties of neural networks and other machine learning systems using the Rocq proof assistant.
A central goal is to give machine learning systems the same level of trustworthiness that we expect from safety-critical software, by providing machine-checked proofs of their behaviour. This work builds on verified mathematical foundations, where formalized probability theory and concentration inequalities provide the rigorous basis for reasoning about learning algorithms.
Differentiable Logics in Rocq
Differentiable logics are a family of logical frameworks that allow neural networks to be trained to satisfy logical specifications by differentiating through the logic. I am working on:
- Formalizing the metatheory of differentiable logics in Rocq, ensuring that the logical connectives and quantifiers behave as expected.
- Extending the formalization with quantifiers, enabling richer specifications for neural network behaviour.
One tool I use and contribute to is the Vehicle language, a domain-specific language for writing neural-network specifications that can be checked formally.
Applications
Current verification targets include:
- Network intrusion detection — verifying that classifiers for network traffic correctly identify malicious patterns while remaining robust to adversarial perturbations.
- Autonomous driving controllers — verifying safety and liveness properties of controllers trained by reinforcement learning.
Secure AI Collaboration across Boundaries (Villum Experiment)
This Villum Experiment project investigates how multiple parties can collaboratively train machine learning models on sensitive data without compromising privacy, by integrating neurosymbolic learning with secure multi-party computation (MPC). The goal is to enable robust and logically consistent learning in domains — such as healthcare and finance — where data sharing is not directly possible.
Alessio Coltellacci joined the group as a postdoc in February 2026 to work on this project, bringing expertise in type theory, automated reasoning, and the verification of SMT solvers from his PhD at Inria Nancy / LORIA (Veridis team).
Related Publications
Reynald Affeldt, Alessandro Bruni, Ekaterina Komendantskaya, Natalia Slusarz, Kathrin Stark: A Foundation for Differentiable Logics using Dependent Type Theory. CoRR abs/2602.23878, 2026 arXiv
Jairo Miguel Marulanda-Giraldo, Ekaterina Komendantskaya, Alessandro Bruni, Reynald Affeldt, Matteo Capucci, Enrico Marchioni: Quantifiers for Differentiable Logics in Rocq. SAIV 2025 PDF
Reynald Affeldt, Alessandro Bruni, Ekaterina Komendantskaya, Natalia Slusarz, Kathrin Stark: Taming Differentiable Logics with Coq Formalisation. ITP 2024 arXiv PDF
Reynald Affeldt, Alessandro Bruni, Ekaterina Komendantskaya, Kathrin Stark, Natalia Slusarz: Exploration of properties of differentiable logics through mechanisation. 2024
Funding
This work is supported by the Villum Experiment grant Secure AI collaboration across Boundaries (DKK 2.11M, 2026–), the Carlsberg Foundation grant VeriFunAI, and through collaborations within the EuroProofNet COST Action network. The application work on network intrusion detection is funded by the NFC and DIREC projects. See my PURE projects page for full project details.