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Linear programming, width-1 CSPs, and robust satisfaction. Ryan O’Donnell Carnegie Mellon University. joint with Gabor Kun (IAS), Suguru Tamaki (Kyoto), Yuichi Yoshida (Kyoto), Yuan Zhou (CMU). CSPs: 2-Sat, 3-Lin(mod 2), 3-Col, ….
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Linear programming, width-1 CSPs, and robust satisfaction Ryan O’Donnell Carnegie Mellon University joint with Gabor Kun (IAS), Suguru Tamaki (Kyoto), Yuichi Yoshida (Kyoto), Yuan Zhou (CMU)
Robust Satisfiability Problem Robust In particular, solves satisfiability.
3-Lin(mod 2): NP-hard to get .51 fraction [Hås97]
All CSPs 3-Col 3-Sat Sat problem in P 3-Lin(G) Robust-sat problem in P Unique-Games 2-Sat 2-Col Horn-k-Sat
All CSPs 3-Col 3-Sat Sat problem in P 3-Lin(G) Bounded Width Unique-Games 2-Sat 2-Col Horn-k-Sat
All CSPs 3-Col 3-Sat Sat problem in P 3-Lin(G) Bounded width Robust-sat problem in P Unique-Games 2-Sat 2-Col Horn-k-Sat
Our results In fact, canonical LP relaxation solves it. In fact, canonical LP solves robust-sat. iff width 1.
All CSPs 3-Col 3-Sat Sat problem in P 3-Lin(G) Bounded width Robust-sat problem in P Unique-Games 2-Sat 2-Col Width 1 Horn-k-Sat
E.g.: Does 2-Col have width 1? Bob can win (play forever), though unsatisfiable.
E.g.: Does 2-Col have width 2? Alice can win.
E.g.: Does 2-Col have width 2? Any unsat. 2-Col instance has an odd cycle: Alice can win.