Axioms - Laws of Boolean Algebra

 Boolean algebra is the algebra of propositions.
Propositions are denoted by letters, such as A, B, x or y, etc.

In the following 
axioms and theorems (laws of boolean algebra), the '+' or 'V' signs represent a logical OR (or conjunction), the '.' or '^' signs represent a logical AND (or disjunction), and '¬' or '~' represent a logical NOT ( or negation).

Every proposition has two possible values: 
1 (or T) when the proposition is true and 0 (or F) when the proposition is false.

The 
negation of A is written as ¬A (or ~A) and read as 'not A'. If A is true then ¬A is false. Conversely, if A is false then ¬A is true.