Groebner
SPolynomial
compute S-polynomials
Calling Sequence
Parameters
Description
Examples
SPolynomial(f, g, T, characteristic=p)
f, g
-
polynomials
T
a MonomialOrder or ShortMonomialOrder
p
(optional) characteristic
SPolynomial(f, g, T) computes an S-polynomial of f and g with respect to the monomial order T. The S-polynomial is a syzygy. It induces a cancellation of leading terms using the smallest possible multiples of f and g.
In commutative domains the S-polynomial of f and g is given by lcmLTf,LTgfLTf−gLTg, where LT(f) denotes the leading term of f with respect to T. In case of Ore algebras the S-polynomial is defined similarly, however since there is no longer a division on monomials the S-polynomial of f and g is defined by c'[f]*t'[f]*f - c'[g]*t'[g]*g where:
t'[f]*LM(f) = t'[g]*LM(g) = lcm(LM(f), LM(g)) where LM(f) denotes the leading monomial of f
t'[f]*LC(f) = c''[f]*t'[f] + lower order terms where LC(f) denotes the leading coefficient of f
t'[g]*LC(g) = c''[g]*t'[g] + lower order terms
c'[f]*c''[f] = c'[g]*c''[g] = c''[f]*c''[g] / gcd(c''[f], c''[g])
An optional argument characteristic=p can be used to specify the ring characteristic when T is a ShortMonomialOrder. The default value is zero.
If T is a ShortMonomialOrder then f and g must be polynomials in the ring implied by T. If T is a MonomialOrder created with the Groebner[MonomialOrder] command, then f and g must be members of the algebra used to define T.
Note that the spoly command is deprecated. It may not be supported in a future Maple release.
withGroebner:
f≔x−13y2−12z3
f≔−12z3−13y2+x
g≔x2−xy+92z
SPolynomialf,g,plexx,y,z
−12xz3−13xy2+xy−92z
SPolynomialf,g,tdegx,y,z
−12xyz3−13x2y2+1104z4+x3
Operators in a Weyl algebra
withOre_algebra:
A≔diff_algebraDx,x,Dy,y,polynom=x,y:
T≔MonomialOrderA,tdegDx,Dy,x,y:
SPolynomialDx+y,Dy−x,T
Dxx+Dyy+2
Operators in a q-calculus algebra
A≔skew_algebracomm=q,qdilat=Sx,x,q:
T≔MonomialOrderA,tdegSx:
SPolynomialSx2−x,xSx,T
−qx2
Operators in a Weyl algebra modulo a prime
A≔diff_algebraDx,x,characteristic=2:
T≔MonomialOrderA,tdegDx:
SPolynomialDx,x2,T
0
Algebraic number coefficients
s≔SPolynomial2−3ix2−x,x2+1+ix,tdegx
s≔3i2+i−3x
evals,i=I
−6+Ix
SPolynomial2−3Ix2−x,x2+1+Ix,tdegx
See Also
Basis
MonomialOrder
Ore_algebra
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