Abstract
We investigate properties ofk-resolution, a restricted version of resolution in which one parent clause must have length at mostk. Starting from a unit-preference strategy, we compare minimal proof lengths of unit-resolution and unrestricted resolution. In particular, we show that the speed-up by using resolution is bound by\(\sqrt t \) if the shortest unit-resolution refutation needst steps. Next we present an algorithm which decides whether the empty clause can be deduced by 2-resolution from a formula Φ and has time complexity O(length(Φ)4). Finally we describe effects onk-resolution if a formula is transformed intot-CNF and show that extended 3-resolution is complete and sound.
Similar content being viewed by others
References
W.F. Dowling and I.H. Gallier, Linear-time algorithms for testing the satisfiability of propositional Horn formulas,I. Logic Programming 3 (1984) 267–284.
E. Eder,Relative Complexities of First Order Calculi (Vieweg, 1992).
G. Gallo and M.G. Scutellà, Polynomially satisfiability problems,Information Processing Letters 29 (1988) 267–284.
A. Haken, The intractability of resolution,TCS 39 (1985) 297–308.
H. Kleine Büning, On generalized Horn formulas andk-resolution,TCS 116 (1993) 405–413.
G.S. Tseitin, On the complexity of derivations in the propositional calculus, in:Structures in Constructive Mathematics and Mathematical Logic, Part II, ed. A.O. Slisenko (1968) pp. 115–125.
L. Wos, D. Carson and G.A. Robinson, The unit preference strategy in theorem proving,AFIPS Conf. Proc. 26 (Spantau Books, Washington, DC).
S. Yamasaki and S. Doshita, The satisfiability problem for a class consisting of Horn sentences and some none-Horn sentences in propositional logic,Information and Control 59 (1983) 1–12.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Buro, M., Büning, H.K. On resolution with short clauses. Ann Math Artif Intell 18, 243–260 (1996). https://doi.org/10.1007/BF02127749
Issue date:
DOI: https://doi.org/10.1007/BF02127749
