QuantFormal

Formal Verification and Learning for Quantitative Systems
An FSTTCS 2025 pre-conference workshop
Date: December 15-16, 2025
Venue: BITS Goa

About the workshop

Quantitative systems—such as timed systems, weighted automata, hybrid automata, and probabilistic models—are fundamental in modeling and analyzing real-world systems where time, resource constraints, or probabilistic behavior are central. The design and verification of such systems demand rigorous formal methods to ensure correctness, efficiency, and robustness in the presence of quantitative parameters.

Formal reasoning techniques in this space have matured significantly over the past two decades. These include automata-theoretic methods for weighted and timed systems, logical foundations for hybrid and probabilistic systems, and algorithmic tools for synthesis and verification. The recent surge in interest around learning-based methods for system modeling and controller synthesis has further enriched the landscape. Moreover, quantitative verification is increasingly being used to evaluate and ensure the trustworthiness and safety of AI-driven systems, helping provide strong guarantees in applications where reliability is essential.

This workshop aims to bring together researchers and practitioners interested in the interplay between formal methods and quantitative models. By focusing on foundational issues, tool development, and emerging directions, this event will provide a platform for exchanging ideas, fostering collaboration, and showcasing advances in formal analysis of quantitative systems.

Schedule

TBA

Topics of Interest

The workshop welcomes contributions from both theoretical and applied perspectives, including but not limited to:

Confirmed Speakers

Singapore Management University

Neural Stochastic Control and Verification with Supermartingale Certificates

Abstract

Learning-based methods, such as reinforcement learning, are receiving increasing attention for solving challenging control tasks. However, the lack of safety assurances about learned controllers poses a significant barrier to their practical deployment. In this talk, we will present a framework for learning and formally verifying neural controllers. The framework is applicable to stochastic control systems, thus also considering environment uncertainty. Given a specification, the framework jointly learns and formally verifies a controller together with a formal certificate of the specification being satisfied, both parametrized as neural networks. Certificates are supermartingale-like objects that can be effectively used to formally reason about stochastic systems in a fully automated fashion. We will show how the framework can be applied to solve reachability, safety, reach-avoidance and stability tasks, as well as a compositional framework allowing us to reason about a more expressive logic of specifications.

Chalmers University of Technology
IIT Bombay
Kyoto University

Specification‑Based Testing of Cyber‑Physical Systems via Black-Box Checking

Abstract

Cyber‑physical systems (CPS), which integrate computational control with physical processes, require high reliability because they are often deployed in safety-critical domains. Ensuring that such systems satisfy their formal specifications is challenging, since modern CPS often contain complex or opaque components, such as deep neural networks, whose internal structures are not fully accessible. Black-box checking (BBC) is a workflow for systematic testing of black-box systems by approximating the system under test as an automaton by active automata learning and verifying the approximate automaton by model checking. This talk presents how to utilize BBC for specification-based testing of CPS, several techniques to improve its efficiency, and a Java toolkit FalCAuN for applying BBC of CPS. FalCAuN is publicly available: https://github.com/MasWag/FalCAuN. An extension of BBC for probabilistic systems will also be discussed.

Bio

Masaki Waga, Ph.D., is an Assistant Professor at the Graduate School of Informatics, Kyoto University, Japan. He received his Ph.D. in Informatics from the Graduate University for Advanced Studies (SOKENDAI), Tokyo, under the supervision of Prof. Ichiro Hasuo, earning the Dean's Award in 2020 for his doctoral research. His research focuses on formal methods for cyber-physical and AI systems, spanning automata theory, runtime verification, testing, and model checking. He is a recipient of Best Paper Awards at ICECCS 2018 (with Étienne André and Ichiro Hasuo) and FORMATS 2019 (the Oded Maler Award), and has held JST research fellowships including ACT-X (2020–2023), PRESTO (2022–2026), and BOOST (2025–2030).

CNRS & ENS Paris-Saclay

More speakers to be added...

Registration

TBA

Organizers

S. Akshay
IIT Bombay
Shibashis Guha
TIFR Mumbai
Suguman Bansal
Georgia Tech