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5.1.96 nres
Syntax:
nres ( ideal_expression, int_expression )
nres ( module_expression, int_expression )
Type:
- resolution
Purpose:
- computes a free resolution of an ideal or module M which is minimized from
the second module on (by the standard basis method).
More precisely, let
then nres computes a free resolution of
where the columns of the matrix
are the given set of generators of M.
If the int expression k is not zero then the computation stops after k steps
and returns a list of modules
nres(M,0) returns a list of n modules where n is the number of
variables of the basering.
Let list L=nres(M,0); then L[1]=M is identical to the input,
L[2] is a minimal set of generators for the first syzygy
module of L[1] , etc.
in the notations from above).
Example:
See
hres;
ideal;
lres;
module;
mres;
res;
resolution;
sres.
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