Groebner
Support
compute the support of a polynomial
Calling Sequence
Parameters
Description
Examples
Support(f, T)
f
-
polynomial or a list or set of polynomials
T
(optional) list or set of variables, MonomialOrder, or ShortMonomialOrder
The Support command returns the list of the monomials present in a polynomial f. It automatically maps onto lists and sets, and can be used to quickly reveal the structure of a large Groebner basis.
An optional second argument T may be a list or set of variables or a MonomialOrder or ShortMonomialOrder. If a monomial order is supplied then the resulting list of monomials is sorted in the monomial order. If T is a list then the monomials are sorted in lexicographical order, or if T is a set then the monomials are not sorted.
with⁡Groebner:
f≔87⁢x⁢y−56⁢x⁢y⁢z2−62⁢x2⁢z3+97⁢x⁢y3⁢z−73⁢y⁢z4
f≔−62⁢x2⁢z3+97⁢x⁢y3⁢z−73⁢y⁢z4−56⁢x⁢y⁢z2+87⁢x⁢y
Here, Support returns an unsorted list of monomials.
Support⁡f
x2⁢z3,x⁢y3⁢z,y⁢z4,x⁢y⁢z2,x⁢y
The monomials are sorted in lexicographic order with x⁢>⁢y⁢>⁢z .
Support⁡f,x,y,z
x2⁢z3,x⁢y3⁢z,x⁢y⁢z2,x⁢y,y⁢z4
The monomials are sorted in graded lexicographic order with x⁢>⁢y⁢>⁢z .
Support⁡f,grlex⁡x,y,z
F≔x2+5⁢y4,x8−8⁢y4,z8+64⁢y2−x8+100
F≔5⁢y4+x2,x8−8⁢y4,−x8+z8+64⁢y2+100
Sometimes it is hard to see the structure of a Groebner basis. Support can quickly reveal the structure.
G≔GroebnerBasis⁡F,plex⁡x,y,z
G≔390625⁢z64+312500000⁢z56+109375000000⁢z48+21874994880000⁢z40+2734360643520000⁢z32+218740742876160000⁢z24+10935189454281097216⁢z16+312260738651419443200⁢z8+3897556646490972160000,264000003515625⁢z56+141792004560937500⁢z48+36975233639881250000⁢z40+5116635466117234680000⁢z32+535841466606972146400000⁢z24−4111661799133622084480000⁢z16+27769709934963826285883486208⁢z8+2305845823963169687985887117312⁢y2+3096625863672405027833148620800,−1320000017578125⁢z56−708960022804687500⁢z48−184876168199406250000⁢z40−25583177330586173400000⁢z32−2679207333034860732000000⁢z24+20558308995668110422400000⁢z16+41295655322303500444480000000⁢z8+288230727995396210998235889664⁢x2+2531291181350238048224000000000
Support⁡G,plex⁡x,y,z
z64,z56,z48,z40,z32,z24,z16,z8,1,y2,z56,z48,z40,z32,z24,z16,z8,1,x2,z56,z48,z40,z32,z24,z16,z8,1
See Also
Groebner basis
InitialForm
LeadingTerm
Monomial Orders
MonomialOrder
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