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2005
Springer

2-Way vs. d-Way Branching for CSP

12 years 1 days ago
2-Way vs. d-Way Branching for CSP
Abstract. Most CSP algorithms are based on refinements and extensions of backtracking, and employ one of two simple “branching schemes”: 2-way branching or d-way branching, for domain size d. The schemes are not equivalent, but little is known about their relative power. Here we compare them in terms of how efficiently they can refute an unsatisfiable instance with optimal branching choices, by studying two variants of the resolution proof system, denoted C-RES and NG-RES, which model the reasoning of CSP algorithms. The tree-like restrictions, tree-C-RES and tree-NG-RES, exactly capture the power of backtracking with 2-way branching and d-way branching, respectively. We give a family instances which require exponential sized search trees for backtracking with d-way branching, but have size O(d2 n) search trees for backtracking with 2way branching. We also give a natural branching strategy with which backtracking with 2-way branching finds refutations of these instances in time ...
Joey Hwang, David G. Mitchell
Added 26 Jun 2010
Updated 26 Jun 2010
Type Conference
Year 2005
Where CP
Authors Joey Hwang, David G. Mitchell
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