QBF encoding of temporal properties and QBF-based verification

SAT and QBF solving techniques have applications in various areas. One area of the applications of SAT-solving is formal verification of temporal properties of transition system models. Because of the restriction on the structure of formulas, complicated verification problems cannot be naturally represented with SAT-formulas succinctly. This paper investigates QBF-applications in this area, aiming at the verification of branching-time temporal logic properties of transition system models. The focus of this paper is on temporal logic properties specified by the extended computation tree logic that allows some sort of fairness, and the main contribution of this paper is a bounded semantics for the extended computation tree logic. A QBF encoding of the temporal logic is then developed from the definition of the bounded semantics, and an implementation of QBF-based verification follows from the QBF encoding. Experimental evaluation of the feasibility and the computational properties of such a QBF-based verification algorithm is reported. © 2014 Springer International Publishing Switzerland.SAT and QBF solving techniques have applications in various areas. One area of the applications of SAT-solving is formal verification of temporal properties of transition system models. Because of the restriction on the structure of formulas, complicated verification problems cannot be naturally represented with SAT-formulas succinctly. This paper investigates QBF-applications in this area, aiming at the verification of branching-time temporal logic properties of transition system models. The focus of this paper is on temporal logic properties specified by the extended computation tree logic that allows some sort of fairness, and the main contribution of this paper is a bounded semantics for the extended computation tree logic. A QBF encoding of the temporal logic is then developed from the definition of the bounded semantics, and an implementation of QBF-based verification follows from the QBF encoding. Experimental evaluation of the feasibility and the computational properties of such a QBF-based verification algorithm is reported. © 2014 Springer International Publishing Switzerland

The problem of interoperability: a common data format for quantum chemistry codes

An XML based format is presented for representing quantities such as molecular geometries, basis sets, and similar information requiring a small amount of data. Preliminary applications using also a HDF5 based format for handling large data are also presented

On the Nature of Sandwiched Chromium Complexes in Exchanged alpha-Zirconium Phosphate

Layered alpha-zirconium hydrogenphosphate monohydrate was prepared by direct precipitation, exchanged with n-propylamine and then by chromium aquacomplexes. The solids were characterized by X-ray diffraction, mass spectrometry, infrared and UV-Visible spectroscopy. The results suggest that monomer complexes form extended, hydrogen bonded, sandwiched monolayers in the interlayer space