De Morgan's laws
The equivalences (i) not (A or B) if and only if not-A and not-B, and (ii) not (A and B), if and only if not-A or not-B, are known as De Morgan's laws, although De Morgan himself gave the equivalent statements in Boolean algebra . Each equivalence is a theorem of the propositional calculus.

Philosophy dictionary. . 2011.

Look at other dictionaries:

  • De Morgan's laws — In formal logic, De Morgan s laws are rules relating the logical operators and and or in terms of each other via negation. With two operands A and B: In another form: NOT (A AND B) = (NOT A) OR (NOT B) NOT (A OR B) = (NOT A) AND (NOT B) The rules …   Wikipedia

  • De Morgan's laws — 1. Logic. two laws, one stating that the denial of the conjunction of a class of propositions is equivalent to the disjunction of the denials of a proposition, and the other stating that the denial of the disjunction of a class of propositions is …   Universalium

  • De Morgan's laws — 1. Logic. two laws, one stating that the denial of the conjunction of a class of propositions is equivalent to the disjunction of the denials of a proposition, and the other stating that the denial of the disjunction of a class of propositions is …   Useful english dictionary

  • De Morgan — is a surname, and may refer to: Augustus De Morgan, mathematician and logician. De Morgan s laws (or De Morgan s theorem), a set of rules from propositional logic. The De Morgan Medal, a mathematics prize awarded by the London Mathematical… …   Wikipedia

  • De Morgan, Augustus — ▪ English mathematician and logician born , June 27, 1806, Madura, India died March 18, 1871, London, Eng.       English mathematician and logician whose major contributions to the study of logic include the formulation of De Morgan s laws and… …   Universalium

  • De Morgan algebra — In mathematics, a De Morgan algebra is a structure A = (A, ∨, ∧, 0, 1, ¬) such that: (A, ∨, ∧, 0, 1) is a bounded distributive lattice, and ¬ is a De Morgan involution: ¬(x ∧ y) =… …   Wikipedia

  • De-Morgan — Augustus De Morgan Augustus De Morgan (* 27. Juni 1806 in Madurai, Indien; † 18. März 1871 in London) war ein englischer Mathematiker. Er war Mitbegründer und erster Präsident der London Mathematical Society …   Deutsch Wikipedia

  • Morgan's Raid — Part of the American Civil War Date June 11 (1963 06 11) – July 26, 1863 ( …   Wikipedia

  • Augustus De Morgan — (1806 1871) Born 27 June 1806( …   Wikipedia

  • Augustus de Morgan — (* 27. Juni 1806 in Madurai, Indien; † 18. März 1871 in London) war ein englischer Mathematiker. Er war Mitbegründer und erster Präsident der London Mathematical Society …   Deutsch Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”