• Boolean Algebra is an algebra wherein values can be truth values ( or ) and operators are logical operators

  • A Proposition is a declarative statement that must be exactly one of TRUE or FALSE. The proposition’s truth value denotes the relation of a proposition to its

Logical Operators

  • Conjunction (AND) - denoted or for sequences It is true if and only if and are both .
PQ
FFF
FTF
TFF
TTT
  • Disjunction (OR) - denoted or for sequences of propositions. It is true if at least one of and are true
PQ
FFF
FTT
TFT
TTT
  • Negation (NOT) - denoted or sometimes . It is the opposite truth value to the value given
P
FT
TF
  • NAND - defined as the negation of the conjunction. It is false only when both inputs are true
PQ
FFT
FTT
TFT
TTF
  • NOR - defined as the negation of the disjunction. It is true only when both inputs are false.
PQ
FFT
FTF
TFF
TTF
  • Material Implication (IF) - denoted . It is defined by the following truth table
PQ
FFT
FTT
TFF
TTT
  • Exclusive OR (XOR) - denoted or for sequences. It is defined as true if exactly an odd number of its inputs are true
PQ
FFF
FTT
TFT
TTF
  • Bidirectional Implication (IFF / XNOR) - denoted or for sequences. It is defined as true if exactly an even number of its inputs are true
PQ
FFT
FTF
TFF
TTT

Properties of Logical Operations

  • Logical operations satisfy the following properties

Double Negation

Identity

Domination

Complements

Commutativity

Associativity

Distributivity

Idempotence

Absorption

Redundancy

Consensus Law

De Morgan’s Laws

Monotonicity

Implications

  1. Contraposition
  2. Import-Export
  3. Negation
  4. Disjunction
  5. Commutativity of antecedents
  6. Distributivity

Links