Back باطل (منطق) Arabic زڕ (لۆژیک) CKB Falso (lógica) Spanish Väär Estonian کذب Persian Falso (lóxica) Galician Falsajo (logiko) IO 거짓 Korean Fałsz Polish Falso (lógica) Portuguese
In logic, false (Its noun form is falsity) or untrue is the state of possessing negative truth value and is a nullary logical connective. In a truth-functional system of propositional logic, it is one of two postulated truth values, along with its negation, truth.[1] Usual notations of the false are 0 (especially in Boolean logic and computer science), O (in prefix notation, Opq), and the up tack symbol .[2][3]
Another approach is used for several formal theories (e.g., intuitionistic propositional calculus), where a propositional constant (i.e. a nullary connective), , is introduced, the truth value of which being always false in the sense above.[4][5][6] It can be treated as an absurd proposition, and is often called absurdity.
- ^ Jennifer Fisher, On the Philosophy of Logic, Thomson Wadsworth, 2007, ISBN 0-495-00888-5, p. 17.
- ^ Willard Van Orman Quine, Methods of Logic, 4th ed, Harvard University Press, 1982, ISBN 0-674-57176-2, p. 34.
- ^ "Truth-value | logic". Encyclopedia Britannica. Retrieved 2020-08-15.
- ^ George Edward Hughes and D.E. Londey, The Elements of Formal Logic, Methuen, 1965, p. 151.
- ^ Leon Horsten and Richard Pettigrew, Continuum Companion to Philosophical Logic, Continuum International Publishing Group, 2011, ISBN 1-4411-5423-X, p. 199.
- ^ Graham Priest, An Introduction to Non-Classical Logic: From If to Is, 2nd ed, Cambridge University Press, 2008, ISBN 0-521-85433-4, p. 105.