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Single Idea 9396

[filed under theme 4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / c. Derivation rules of PL ]

Full Idea

Double Negation (DN): Given A, we may derive ¬¬A as a conclusion, and vice versa. The conclusion depends on the assumptions of the premiss.

Clarification

¬ is 'not'

Gist of Idea

DN: Given A, we may derive ¬¬A

Source

E.J. Lemmon (Beginning Logic [1965], 1.5)

Book Ref

Lemmon,E.J.: 'Beginning Logic' [Nelson 1979], p.40