A Lean Approach to Building Valid Model-Based Safety Arguments
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
In recent decades, cyber-physical systems developed using Model-Driven Engineering (MDE) techniques have become ubiquitous in safety-critical domains. Safety assurance cases (ACs) are structured arguments designed to comprehensively show that such systems are safe; however, the reasoning steps, or strategies, used in AC arguments are often informal and difficult to rigorously evaluate. Consequently, AC arguments are prone to fallacies, and unsafe systems have been deployed as a result of fallacious ACs. To mitigate this problem, prior work [32] created a set of provably valid AC strategy templates to guide developers in building rigorous ACs. Yet instantiations of these templates remain error-prone and still need to be reviewed manually. In this paper, we report on using the interactive theorem prover Lean to bridge the gap between safety arguments and rigorous model-based reasoning. We generate formal, modelbased machine-checked AC arguments, taking advantage of the traceability between model and safety artifacts, and mitigating errors that could arise from manual argument assessment. The approach is implemented in an extended version of the MMINT-A model management tool [10]. Implementation includes a conversion of informal claims into formal Lean properties, decomposition into formal sub-properties and generation of correctness proofs. We demonstrate the applicability of the approach on two safety case studies from the literature.
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it