Definition
Maximum Exact-4-SAT Optimisation Problem
Instance: A CNF formula
, where each clause consists of exactly four literals on four distinct variables. Feasible solutions: All truth assignments
. Objective: Maximise the number of satisfied clauses:
Hereis when holds and otherwise. “Exact-4” specifies clause length, not a requirement that exactly one literal be true. Clauses may share variables with other clauses.