Relative Size of Certain Polynomial Time Solvable Subclasses of Satisfiability,
Abstract
We determine, according to a certain measure, the relative sizes of several well known polynomially solvable subclasses of SAT. The measure we adopt is the probability that randomly selected k-SAT formulas belong to the subclass of formulas in question. This probability is a function of the ratio r of clauses to variables and we determine those ranges of this ratio that result in membership with high probability. We show, for any fixed r > 4/(k(k - 1)), the probability that a random formula is SLUR, q-Horn, extended Horn, CC-balanced, or renamable Horn tends to 0 as n approaches infinity. We also show that most random unsatisfiable formulas are not members of one of these subclasses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1997
- Accession Number
- ADA326040
Entities
People
- J. Franco
Organizations
- University of Cincinnati