 The prototypical example of a congruence relation is congruence modulo formula_1 on the set of integers.For a given positive integer formula_1, two integers formula_3 and formula_4 are called congruent modulo formula_1, written
if formula_7 is divisible by formula_1 (or equivalently if formula_3 and formula_4 have the same remainder when divided by formula_1).For example, formula_12 and formula_13 are congruent modulo formula_14,

since formula_16 is a multiple of 10, or equivalently since both formula_12 and formula_13 have a remainder of formula_19 when divided by formula_14.