** Let
be a field and
be a univariate polynomial
of positive degree
.
We denote by
the residue class ring
.
Since we do not assume that
is an irreducible
polynomial, some non-zero elements in
may not have an inverse.
This motivates the following notion.
For any
, with
, we call ***quasi-inverse* of
, any
, with
, such that either
or
holds.

*Marc Moreno Maza *

2008-03-18