Logical conjunction

AND
Definition	${\displaystyle xy}$
Truth table	${\displaystyle (1000)}$
Logic gate
Normal forms
Disjunctive	${\displaystyle xy}$
Conjunctive	${\displaystyle xy}$
Zhegalkin polynomial	${\displaystyle xy}$
Post's lattices
0-preserving	yes
1-preserving	yes
Monotone	no
Affine	no
v t e

Logical connectives
AND ${\displaystyle A\land B}$, ${\displaystyle A\cdot B}$, ${\displaystyle AB}$, ${\displaystyle A\&B}$, ${\displaystyle A\&\&B}$ equivalent ${\displaystyle A\equiv B}$, ${\displaystyle A\Leftrightarrow B}$, ${\displaystyle A\leftrightharpoons B}$ implies ${\displaystyle A\Rightarrow B}$, ${\displaystyle A\supset B}$, ${\displaystyle A\rightarrow B}$ NAND ${\displaystyle A{\overline {\land }}B}$, ${\displaystyle A\uparrow B}$, ${\displaystyle A\mid B}$, ${\displaystyle {\overline {A\cdot B}}}$ nonequivalent ${\displaystyle A\not \equiv B}$, ${\displaystyle A\not \Leftrightarrow B}$, ${\displaystyle A\nleftrightarrow B}$ NOR ${\displaystyle A{\overline {\lor }}B}$, ${\displaystyle A\downarrow B}$, ${\displaystyle {\overline {A+B}}}$ NOT ${\displaystyle \neg A}$, ${\displaystyle -A}$, ${\displaystyle {\overline {A}}}$, ${\displaystyle \sim A}$ OR ${\displaystyle A\lor B}$, ${\displaystyle A+B}$, ${\displaystyle A\mid B}$, ${\displaystyle A\parallel B}$ XNOR ${\displaystyle A\ {\text{XNOR}}\ B}$ XOR ${\displaystyle A{\underline {\lor }}B}$, ${\displaystyle A\oplus B}$ converse ${\displaystyle A\Leftarrow B}$, ${\displaystyle A\subset B}$, ${\displaystyle A\leftarrow B}$
Related concepts
Propositional calculus Predicate logic Boolean algebra Truth table Truth function Boolean function Functional completeness Scope (logic)
Applications
Digital logic Programming languages Mathematical logic Philosophy of logic
Category
v t e

In logic, mathematics and linguistics, and (${\displaystyle \wedge }$) is the truth-functional operator of conjunction or logical conjunction. The logical connective of this operator is typically represented as ${\displaystyle \wedge }$^[1] or ${\displaystyle \&}$ or ${\displaystyle K}$ (prefix) or ${\displaystyle \times }$ or ${\displaystyle \cdot }$^[2] in which ${\displaystyle \wedge }$ 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., ${\displaystyle A\land B}$ is true if and only if ${\displaystyle A}$ is true and ${\displaystyle B}$ is true.

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

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

• In natural language, the denotation of expressions such as English "and";
• In programming languages, the short-circuit and control structure;
• In set theory, intersection.
• In lattice theory, logical conjunction (greatest lower bound).

Notation

And is usually denoted by an infix operator: in mathematics and logic, it is denoted by ${\displaystyle \wedge }$ (Unicode U+2227 ∧ LOGICAL AND),^[1] ${\displaystyle \&}$ or ${\displaystyle \times }$; in electronics, ${\displaystyle \cdot }$; and in programming languages, &, &&, or and. In Jan Łukasiewicz's prefix notation for logic, the operator is ${\displaystyle K}$, 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.^[2][1]

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

The truth table of ${\displaystyle A\land B}$:^[1][2]

${\displaystyle A}$	${\displaystyle B}$	${\displaystyle A\land B}$
F	F	F
F	T	F
T	F	F
T	T	T

Zdroj:https://en.wikipedia.org?pojem=Logical_AND
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