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2.3 module
Modules are left submodules of a free module over the basering with basis
gen(1) , gen(2) , ... .
They are represented by lists of vectors
(vector data type is the same as in SINGULAR)
which generate the submodule.
Like vectors they
can only be defined or accessed with respect to a basering.
If
is a submodule of
(
is the basering) generated by vectors
, then
may be considered as the generators of relations of
between the canonical generators gen(1) ,...,gen(n) .
Hence any finitely generated
-module can be represented in PLURAL
by its module of relations. The assignments
module M=v1,...,vk; matrix A=M;
create the presentation matrix of size
n k for
/M,i.e., the columns of A are the vectors
which generate M.
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