Disjunctive Normal Form (DNF) is when a formula: ?
- contains no connectives other than conjunction, disjunction and negation.
- only applies negation to propositional symbols (within literals)
- no disjunction appears in a sub-formula of a formula whose main connective is conjunction
Alternatively, you can see it as a disjunction of one or more formulae, each of which is a conjunction of one or more literals.