Model Checking modulo Strong Proof Systems

Descrizione del progetto

Sfruttare dimostrazioni solide per un’informatica affidabile

Garantire il corretto funzionamento dei sistemi informatici è fondamentale nella vita moderna; ciononostante, la verifica automatica rimane una sfida tecnica di non poco conto. Sebbene la verifica dei modelli consenta di valutare la correttezza ricercando le dimostrazioni, i sistemi di dimostrazione più potenti sono spesso troppo complessi perché i computer possano gestirli in modo efficiente. Il progetto StrongMC, finanziato dal CER, mira ad affrontare questo problema sviluppando algoritmi che utilizzano sistemi di dimostrazione robusti, consentendo in tal modo di ottenere dimostrazioni molto più brevi. Il progetto si concentrerà sull’integrazione di questi sistemi nelle procedure decisionali e sulla creazione di algoritmi basati sul sistema di risoluzione esteso, valutandone al contempo le prestazioni, con l’obiettivo finale di gettare nuove basi teoriche che rendano la verifica dei modelli più pratico, favorendone la diffusione su larga scala e migliorandone l’affidabilità tecnologica.

Obiettivo

Ensuring that computerized systems adhere to their specifications is of paramount importance to our everyday life. Model Checking (MC) is an automatic formal verification technique for establishing a system’s correctness. Given a model and a specification, it can construct a proof of whether the specification is valid in that model or not.

Proof systems provide formal proof for the validity of a statement under a given set of axioms and are a powerful tool when applying logic in automated reasoning. MC can be viewed as a proof-search algorithm that operates in some proof system.

While MC is widely used in the industry to rigorously establish correctness of computerized systems, its application remains a challenge due to the complexity of implementing efficient proof-search algorithms that construct proofs automatically.

The goal of StrongMC is to develop the theory and algorithms to enable the use of strong proof systems, which admit short proofs, in model checking.

There is an inherent trade-off between the strength of a proof system and the ability to implement an efficient proof-search algorithm for it. As the strength of the proof system increases, so does the size of the search space, making proof-search algorithms intractable and hence our goal is ambitious and challenging. Yet, based on our preliminary results, we conjecture that strong proof systems can be used efficiently in model checking. By probing three thrusts, we aim to tackle this challenge: (1) use decision procedures that utilize strong proof systems in MC; (2) develop MC algorithms that are based on the Extended Resolution proof system; (3) Analyzing the complexity and efficiency of MC algorithms that use strong proof systems from both theoretical and practical points of view.

We expect the new theoretical foundation and the enhanced MC algorithms will lead to the widespread practical adoption of MC, while also having an important impact on many related fields in Formal Methods.