Phrase guide
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.
noun
Either of two laws in formal logic which state that:
The negation of a conjunction is the disjunction of the negations; expressed in propositional logic as: ¬ (p ∧ q) ⇔ (¬ p) ∨ (¬ q)
Definition source: English Wiktionary via Wiktextract
Topics: human-sciences, logic, mathematics, philosophy, sciences
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
noun
Either of two laws in formal logic which state that:
The negation of a disjunction is the conjunction of the negations; expressed in propositional logic as: ¬ (p ∨ q) ⇔ (¬ p) ∧ (¬ q)
Definition source: English Wiktionary via Wiktextract
Topics: human-sciences, logic, mathematics, philosophy, sciences
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
noun
Either of two laws in set theory which state that:
The complement of a union is the intersection of the complements; as expressed by: (A ∪ B)′ = A′ ∩ B′
Definition source: English Wiktionary via Wiktextract
Topics: mathematics, sciences
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
noun
Either of two laws in set theory which state that:
The complement of an intersection is the union of the complements; as expressed by: (A ∩ B)′ = A′ ∪ B′
Definition source: English Wiktionary via Wiktextract
Topics: mathematics, sciences
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
noun
Any of various laws similar to De Morgan’s laws for set theory and logic; for example: ¬∀x P(x) ⇔ ∃x ¬P(x)
Definition source: English Wiktionary via Wiktextract
Usage: broadly
Topics: mathematics, sciences
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
History
Named after the British mathematician and logician Augustus De Morgan (1806–1871), who first formulated the laws in formal propositional logic.
Across languages
10 source translations are retained for this English entry.
