The ideal quotient ,
also called a colon ideal, is the ideal in a commutative
ring
defined by
where
and
are ideals. It is an analog of division
for ideals.
If , then
iff
for every
, ...,
. In particular, quotienting by a principal
ideal
requires only
(Jensen 2014, p. 67).
For positive integers and
, the ring of integers gives
where
is the greatest common divisor. Thus
, while
. Taking
the union of the quotients by successive powers
of an ideal gives ideal
saturation.