Issy: A Comprehensive Tool for Specification and Synthesis of Infinite-State Reactive Systems

2025-02-05

AI Summary

This work addresses the specification and synthesis challenges for infinite-state reactive systems. Existing approaches suffer from heterogeneous specification formalisms, error-prone manual encoding, and difficulties in comparative evaluation. To resolve these issues, we propose a unified, implementable automation framework: (1) a expressive specification language that integrates temporal logic (LTL/GR(1)) with infinite-state games; (2) a multi-algorithmic solver combining symbolic model checking, abstract interpretation, SMT solving, and strategy extraction; and (3) a high-level user interface with a machine-readable compilation backend. Experimental evaluation on large-scale benchmarks demonstrates competitive performance against state-of-the-art tools, a significant reduction in specification errors, and real-world impact—including adoption by multiple research groups and contributions to community standardization efforts.

Technology Category

• Knowledge Representation and Reasoning: Automated Reasoning and Theorem Proving
• Constraint Satisfaction and Optimization: Satisfiability Modulo Theories
• Multiagent Systems: Distributed Problem Solving

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Semantics and Knowledge: Data modeling to support human-machine intelligence, including LLMs agents, intelligent system behavior, explanations, and user-friendly interactions

Abstract

The synthesis of infinite-state reactive systems from temporal logic specifications or infinite-state games has attracted significant attention in recent years, leading to the emergence of novel solving techniques. Most approaches are accompanied by an implementation showcasing their viability on an increasingly larger collection of benchmarks. Those implementations are -- often simple -- prototypes. Furthermore, differences in specification formalisms and formats make comparisons difficult, and writing specifications is a tedious and error-prone task. To address this, we present Issy, a tool for specification, realizability, and synthesis of infinite-state reactive systems. Issy comes with an expressive specification language that allows for combining infinite-state games and temporal formulas, thus encompassing the current formalisms. The realizability checking and synthesis methods implemented in Issy build upon recently developed approaches and extend them with newly engineered efficient techniques, offering a portfolio of solving algorithms. We evaluate Issy on an extensive set of benchmarks, demonstrating its competitiveness with the state of the art. Furthermore, Issy provides tooling for a general high-level format designed to make specification easier for users. It also includes a compiler to a more machine-readable format that other tool developers can easily use, which we hope will lead to a broader adoption and advances in infinite-state reactive synthesis.

Problem

• Synthesis of infinite-state reactive systems
• Comparison of specification formalisms
• Easier user specification writing

Innovation

• Combines infinite-state games
• Extends recent synthesis methods
• Offers user-friendly specification tooling