# ConStaBL -- A Fresh Look at Software Engineering with State Machines

**Authors:** Karthika Venkatesan, Sujit Kumar Chakrabarti  
**arXiv:** [2307.03790](https://arxiv.org/abs/2307.03790)  
**Date:** 2023-07-07  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2307.03790v2/

## Key points

- Paper titled "ConStaBL -- A Fresh Look at Software Engineering with State Machines" by Karthika Venkatesan and Sujit Kumar Chakrabarti
- Introduces extended operational semantics for statecharts with concurrency
- Statechart is a visual modeling language used for systems
- Builds upon previous work on modular statecharts with local variables
- Updated semantics ensures no transition conflicts in simulations, stricter than other available semantics for statecharts
- Allows for arbitrary interleaving of concurrently executing action code, enabling more precise system modeling and upstream analysis
- Utilizes simulation algorithm and establishes criteria to define conflicting transitions and valid simulations
- Semantics is executable, enabling simulation of statechart models and verification of correctness
- Introduces novel concept of fuzz testing for non-trivial-sized statechart models to identify issues that would have been challenging to discover through manual inspection alone
- Provides enhanced understanding of state machines through introduction of local variables and updated operational semantics for concurrency in statecharts
- Executable semantics enable accurate simulation and verification
- Introduces new approach to testing these models using fuzzing techniques, contributing to the field of software engineering

## Summary

The paper titled "ConStaBL -- A Fresh Look at Software Engineering with State Machines" by Karthika Venkatesan and Sujit Kumar Chakrabarti introduces an extended operational semantics for statecharts with concurrency. Statechart is a visual modeling language used for systems, and the authors build upon their previous work on modular statecharts with local variables. The authors' variant of the statechart includes local variables that interact significantly with the rest of the language semantics. Their updated semantics ensures no transition conflicts in simulations, making it stricter than other available semantics for statecharts. This allows for arbitrary interleaving of concurrently executing action code, enabling more precise system modeling and upstream analysis. To present their operational semantics, the authors utilize a simulation algorithm and establish criteria to define conflicting transitions and valid simulations. Importantly, their semantics is executable which enables simulation of statechart models and verification of correctness. Additionally, they introduce a novel concept of fuzz testing for non-trivial-sized statechart models to identify issues that would have been challenging to discover through manual inspection alone. In summary, this paper provides an enhanced understanding of state machines through the introduction of local variables and updated operational semantics for concurrency in statecharts. The authors' executable semantics enable accurate simulation and verification while also introducing a new approach to testing these models using fuzzing techniques which contributes to the field of software engineering.