Our focus in this section is on finitely presented modules over rings from the following list:
- multivariate polynomial rings (OSCAR type
- quotients of multivariate polynomial rings (OSCAR type
- localizations of the above rings (OSCAR types
Hence, if not mentioned otherwise, the word module refers to a finitely presented module over a ring of one of the above types. Offering a sparse way of implementing free modules, the OSCAR type
FreeMod provides the basis for implementing all modules discussed here. More concretely, the general way of implementing a module is to represent it as a subquotient, that is, as a submodule of a quotient of a free module. Note that subquotients form the smallest class of modules which naturally includes both submodules and quotients of free modules.
Most functions in this section rely on Gröbner (standard) bases techniques. Thus, the functions should not be applied to modules over rings other than those from the list above. See the Linear Algebra chapter for module types which are designed to handle modules over Euclidean domains.
For simplicity of the presentation in what follows, functions are often only illustrated by examples with focus on modules over multivariate polynomial rings, but work similarly for modules over a ring of any of the above types.