A Laurent polynomial with coefficients in the field is an algebraic object that is typically expressed in the
form
where the
are elements of
,
and only finitely many of the
are nonzero. A Laurent polynomial
is an algebraic object in the sense that it is treated as a polynomial
except that the indeterminant "
" can also have negative powers.
Expressed more precisely, the collection of Laurent polynomials with coefficients in a field form a ring, denoted
, with ring operations given
by componentwise addition and multiplication according to the relation
for all
and
in the integers. Formally, this is equivalent to saying
that
is the group ring of the integers
and the field
. This corresponds to
(the polynomial ring in
one variable for
)
being the group ring or monoid
ring for the monoid of natural numbers and the field
.