Mining definitions in Kissat with Kittens.

Bounded variable elimination is one of the most important preprocessing techniques in SAT solving. It benefits from discovering functional dependencies in the form of definitions encoded in the CNF. While the common approach pioneered in SatELite relies on syntactic pattern matching, our new approach uses cores produced by an embedded SAT solver, Kitten. In contrast to a similar semantic technique implemented in Lingeling based on BDD algorithms to generate irredundant CNFs, our new approach is able to generate DRAT proofs. We further discuss design choices for our embedded SAT solver Kitten. Experiments with Kissat show the effectiveness of this approach.

A Verified SAT Solver Framework with Learn, Forget, Restart, and Incrementality.

We developed a formal framework for conflict-driven clause learning (CDCL) using the Isabelle/HOL proof assistant. Through a chain of refinements, an abstract CDCL calculus is connected first to a more concrete calculus, then to a SAT solver expressed in a functional programming language, and finally to a SAT solver in an imperative language, with total correctness guarantees. The framework offers a convenient way to prove metatheorems and experiment with variants, including the Davis-Putnam-Logemann-Loveland (DPLL) calculus. The imperative program relies on the two-watched-literal data structure and other optimizations found in modern solvers. We used Isabelle's Refinement Framework to automate the most tedious refinement steps. The most noteworthy aspects of our work are the inclusion of rules for forget, restart, and incremental solving and the application of stepwise refinement.

Long Term Stability Evaluation of Prostacyclin Released from Biomedical Device through Turbiscan Lab Expert.

Therapeutic guidelines indicate prostacyclin as the first line of treatment in inflammation and vascular diseases. Prostacyclins prevent formation of the platelet plug involved in primary hemostasis by inhibiting platelet activation and, combined with thromboxane, are effective vasodilators in vascular damage. Trans-Atlantic Inter-Society Consensus Document on Management of Peripheral Arterial Disease II guidelines indicates prostacyclins; in particular, Iloprost, as the first therapeutic option for treating peripheral arterial disease. However, therapeutic efficacy of Iloprost has witnessed several drawbacks that have occurred in patients receiving repeated weekly administration of the drug by intravenous infusions. Adverse reactions arose under perfusion with Iloprost for 6 h and patient compliance was drastically decreased. Biomedical devices could provide a suitable alternative to overcome these drawbacks. In particular, elastomeric pumps, filled with Iloprost isotonic solution, could slowly release the drug, thus decreasing its side effects, representing a valid alternative to hospitalization of patients affected by peripheral arterial disease. However, the home therapy treatment of patients requires long-term stability of Iloprost in solution-loaded elastomeric pumps. The aim of this work was to investigate the long-term stability of Iloprost isotonic solution in biomedical devices using Turbiscan technology. Turbiscan Lab Expert (L'Union, France) predicts the long-term stability of suspensions, emulsions and colloidal formulations by measuring backscattering and transmission of particulates dispersed in solution. The formulations were evaluated by measuring the variation of physical-chemical properties of colloids and suspensions as a function of backscattering and transmission modifications. In addition, the release profile of Iloprost isotonic solution from the biomedical device was evaluated.