suivant: Build a polynomial from
monter: Gröbner basis and Gröbner
précédent: Gröbner basis : gbasis
Table des matières
greduce has three arguments : a multivariate
a vector made of polynomials which is supposed to be a Gröbner
basis, and a vector of variable names.
Gröbner reduction : greduce
greduce returns the reduction of
the polynomial given as first argument
with respect to the Gröbner basis given as the second argument.
It is 0 if and only if the polynomial belongs to the ideal.
that is to say
xy - 1 = (y2 -2) mod I where I is the ideal
generated by the Gröbner basis
[x2 - y2, 2xy - y2, y3], because
y2 - 2 is the euclidian division rmainder of 2(xy - 1) by
G2 = 2xy - y2.
Like gbasis (cf. 1.27.1),
greduce may have more than 3 arguments to specify ordering and
algorithm if they differ from the default (lexicographic ordering).
giac documentation written by Renée De Graeve and Bernard Parisse