Definition: A literal is a boolean variable, possibly negated. Examples: p, ¬q
Definition: A boolean expression is said to be in disjunctive normal form (DNF) if it has the form
where each Ei is a conjunction of (one or more) literals.
Example: (a ∧ ¬b ∧ c) ∨ (¬a ∧ b) ∨ (b ∧ ¬ c)
Definition: A boolean expression is said to be in conjunctive normal form (CNF) if it has the form
where each Ei is a disjunction of (one or more) literals.
Example: (a ∨ ¬b ∨ c) ∧ (¬a ∨ b) ∧ (b ∨ ¬ c)