On generalized Horn formulas and k-resolution
نویسندگان
چکیده
منابع مشابه
Recognizing Renamable Generalized Propositional Horn Formulas Is NP-complete
Yamasaki and Doshita have defined an extension of the class of propositional Horn formulas; later, Gallo and Scutellà generalized this class to a hierarchy Γ0 ⊆ Γ1 ⊆ . . . ⊆ Γk ⊆ . . ., where Γ0 is the set of Horn formulas and Γ1 is the class of Yamasaki and Doshita. For any fixed k, the propositional formulas in Γk can be recognized in polynomial time, and the satisfiability problem for Γk for...
متن کاملOn Finding Solutions for Extended Horn Formulas
In this note we present a simple quadratic-time algorithm for solving the satissability problem for a special class of boolean formulas. This class properly contains the class of extended Horn formulas 1] and balanced formulas 2, 4]. Previous algorithms for these classes require testing membership in the classes. However, the problem of recognizing balanced formulas is complex, and the problem ...
متن کاملOn generalized averaged Gaussian formulas
We present a simple numerical method for constructing the optimal (generalized) averaged Gaussian quadrature formulas which are the optimal stratified extensions of Gauss quadrature formulas. These extensions exist in many cases in which real positive Kronrod formulas do not exist. For the Jacobi weight functions w(x) ≡ w(α,β)(x) = (1− x)α(1 + x)β (α, β > −1) we give a necessary and sufficient ...
متن کاملHydras: Directed Hypergraphs and Horn Formulas
We introduce a new graph parameter, the hydra number, arising from the minimization problem for Horn formulas in propositional logic. The hydra number of a graph G = (V, E) is the minimal number of hyperarcs of the form u, v → w required in a directed hypergraph H = (V, F ), such that for every pair (u, v), the set of vertices reachable in H from {u, v} is the entire vertex set V if (u, v) ∈ E,...
متن کاملDependency Quantified Horn Formulas: Models and Complexity
Dependency quantified Boolean formulas (DQBF ) extend quantified Boolean formulas with Henkin-style partially ordered quantifiers. It has been shown that this is likely to yield more succinct representations at the price of a computational blow-up from PSPACE to NEXPTIME. In this paper, we consider dependency quantified Horn formulas (DQHORN ), a subclass of DQBF, and show that the computationa...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 1993
ISSN: 0304-3975
DOI: 10.1016/0304-3975(93)90331-m