Encyclopedia > Laws of logic

  Article Content

Laws of logic

The following laws of logic are valid in propositional logic and can be proved with truth tables. They are also valid in any boolean algebra. See logical operator for the meaning of the symbols.

Summary of the Laws of Logic
Idempotent p ∨ p ≡ p
p ∧ p ≡ p
Associative (p ∧ q ) ∧ r ≡ p ∧ ( q ∧ r )
(p ∨ q ) ∨ r ≡ p ∨ ( q ∨ r )
Commutative p ∧ q ≡ q ∧ p
p ∨ q ≡ q ∨ p
Distributive p ∨ ( q ∧ r ) ≡ ( p ∨ q ) ∧ ( p ∨ r )
p ∧ ( q ∨ r ) ≡ ( p ∧ q ) ∨ ( p ∧ r )
Identity p ∧ T ≡ p
p ∨ F ≡ p
Annihilation[?] p ∨ T ≡ T
p ∧ F ≡ F
Complement[?] p ∨ ¬ p ≡ T
p ∧ ¬ p ≡ F
¬ T ≡ F
¬ F ≡ T
Involution[?] ¬ ¬ p ≡ p
DeMorgan's p ∨ q ≡ ¬ ( ¬ p ∧ ¬ q )
p ∧ q ≡ ¬ ( ¬ p ∨ ¬ q )
Absorption[?] p ∧ ( p ∨ q ) ≡ p
p ∨ ( p ∧ q ) ≡ p



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Canadian Charter of Rights and Freedoms

... rights as are accepted as in Canada (Article 8(2) ECHR: except such as is in accordance with the law and is necessary in a democratic society); limits on freedom of ...

 
 
 
This page was created in 40.2 ms