TeXipedia

lrArr

Represents a double-headed horizontal arrow indicating a bidirectional relationship or equivalence between mathematical expressions.

Overview

Commonly employed in mathematical logic, set theory, and formal proofs to denote logical equivalence, mutual implication, or reversible transformations.

  • Essential in mathematical reasoning to show if-and-only-if relationships
  • Frequently used in algebraic manipulations to indicate steps that can be reversed
  • Appears in computer science and discrete mathematics for showing bijective mappings
  • Useful in formal definitions and theorem statements where bidirectional implications are crucial

Examples

Logical equivalence in a mathematical statement

pqrp \land q \lrArr r
p \land q \lrArr r

Showing bidirectional implication between expressions

x2=4x=±2x^2 = 4 \lrArr x = \pm 2
x^2 = 4 \lrArr x = \pm 2

Demonstrating equivalence of mathematical definitions

f is continuouslimxaf(x)=f(a)f\text{ is continuous} \lrArr \lim_{x \to a} f(x) = f(a)
f\text{ is continuous} \lrArr \lim_{x \to a} f(x) = f(a)