A bidirectional arrow symbol representing logical equivalence, mutual implication, or reversible processes in mathematics.
Examples
Logical equivalence in mathematical logic
p \lrarr q \text{ means 'p if and only if q'}
Bijective function notation
f: X \lrarr Y \text{ denotes a bijective mapping}
Mathematical equivalence statement
x^2 = 4 \lrarr x = \pm 2