Tight Bounds on the Approximability of Almost-satisfiable Horn SAT and Exact Hitting Set}

We study the approximability of two natural Boolean constraint satisfaction problems: Horn satisfiability and exact hitting set. Under the Unique Games conjecture, we prove the following optimal inapproximability and approximability results for finding an assignment satisfying as many constraints as possible given a near-satisfiable instance.

• Type: Journal
• Year: 2010
• Where: ECCC
• Authors: Venkatesan Guruswami, Yuan Zhou
• Keywords: Approximability, ECCC 2010, Natural Boolean, Unique Games Conjecture