Math Fundamentals18 sections · 814 units
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De Morgan's Laws

Negating complex expressions

De Morgan's Laws show how to negate AND and OR expressions. Named after Augustus De Morgan, who formulated them in the 1840s.

First law: ¬(A∧B)=¬A∨¬B\neg(A \land B) = \neg A \lor \neg B. In code: !(a && b) equals !a || !b. Negate an AND by negating each part and changing AND to OR.

Second law: ¬(A∨B)=¬A∧¬B\neg(A \lor B) = \neg A \land \neg B. In code: !(a || b) equals !a && !b. Negate an OR by negating each part and changing OR to AND.