The equivalent symbol is used in modular arithmetic to express “wrap-around” behavior. Typically, the symbol is used in an expression like this:
In plain language, this means the angle is equivalent to the angle . Conceptually the two directions expressed by the angles are the same, so it is convenient to have a notation that expresses that relationship.
The equivalent operator is used to express that two expressions are equivalent, although not necassarily equal.
The modulus operator returns the remainder of dividing the first expression by the second expression.