From Wolfram MathWorld:
A statement is in conjunctive normal form if it is a conjunction (sequence of ANDs) consisting of one or more conjuncts, each of which is a disjunction (OR) of one or more literals (i.e., statement letters and negations of statement letters; Mendelson 1997, p. 30).
A 2-CNF formula is a CNF formula such that every clause has at most two literals.
Is it true that every CNF formula have an equivalent 2-CNF formula? How do you dis/prove this statement?