Definition of de morgan's laws in English English dictionary
By analogy, the pair of laws in set theory which state that the complement of the intersection of two sets is equal to the union of their complements, and the complement of a union of two sets is equal to the intersection of their complements
The laws of formal logic that state that the negation of a conjunction of two terms is equivalent to the disjunction of the negations of each of the terms, and the negation of a disjunction of two terms is equivalent to the conjunction of the negations of each of the terms