Improving SAT Modulo ODE for Hybrid Systems Analysis by Combining Different Enclosure Methods
Résumé
Aiming at automatic verification and analysis techniques for hybrid systems, we present a novel combination of enclosure methods for ordinary differential equations (ODEs) with the iSAT solver for large Boolean combinations of arithmetic constraints. Improving on our pre- vious work, the contribution of this paper lies in combining iSAT with VNODE-LP, as a state-of-the-art enclosure method for ODEs, and with bracketing systems which exploit monotonicity properties to find enclo- sures for problems that VNODE-LP alone cannot enclose tightly. We apply our method to the analysis of a non-linear hybrid system by solv- ing predicative encodings of an inductive stability argument and evaluate the impact of different methods and their combination.