\equivThe symbol \equiv is used to denote equivalence relations in mathematics. It signifies that two expressions are equivalent in some context, such as congruence in modular arithmetic, logical equivalence in logic, or definitional equality in mathematics.
Congruence relation in modular arithmetic, meaning a and b have the same remainder when divided by n.
a \equiv b \pmod{n}Logical equivalence, indicating that functions f and g yield the same result for all x in their domain.
f(x) \equiv g(x)Definitional equality, showing that the expression x^2 - 1 is identically equal to (x-1)(x+1).
x^2 - 1 \equiv (x-1)(x+1)