Logical conjunction explained

Logical conjunction
Other Titles:AND
Venn Diagram:Venn0001.svg
Definition:

xy

Truth Table:

(1000)

Logic Gate:AND_ANSI.svg
Dnf:

xy

Cnf:

xy

Zhegalkin:

xy

0-Preserving:yes
1-Preserving:yes
Monotone:no
Affine:no
Self-Dual:no

In logic, mathematics and linguistics, and (

\wedge

) is the truth-functional operator of conjunction or logical conjunction. The logical connective of this operator is typically represented as

\wedge

[1] or

\&

or

K

(prefix) or

x

or

[2] in which

\wedge

is the most modern and widely used.

The and of a set of operands is true if and only if all of its operands are true, i.e.,

A\landB

is true if and only if

A

is true and

B

is true.

An operand of a conjunction is a conjunct.[3]

Beyond logic, the term "conjunction" also refers to similar concepts in other fields:

Notation

And is usually denoted by an infix operator: in mathematics and logic, it is denoted by

\wedge

(Unicode),

\&

or

x

; in electronics,

; and in programming languages, &, &&, or and. In Jan Łukasiewicz's prefix notation for logic, the operator is

K

, for Polish koniunkcja.[4]

Definition

Logical conjunction is an operation on two logical values, typically the values of two propositions, that produces a value of true if and only if (also known as iff) both of its operands are true.

The conjunctive identity is true, which is to say that AND-ing an expression with true will never change the value of the expression. In keeping with the concept of vacuous truth, when conjunction is defined as an operator or function of arbitrary arity, the empty conjunction (AND-ing over an empty set of operands) is often defined as having the result true.

Truth table

Notes and References

  1. Web site: 2019-08-13. 2.2: Conjunctions and Disjunctions. 2020-09-02. Mathematics LibreTexts. en.
  2. Web site: Conjunction, Negation, and Disjunction. 2020-09-02. philosophy.lander.edu.
  3. Book: Beall, Jeffrey C. . Logic: the basics . 2010 . Routledge . 978-0-203-85155-5 . 1. publ . The basics . London . 17 . en.
  4. [Józef Maria Bocheński]