RegularChains[ConstructibleSetTools]
PolynomialMapImage
compute the image of a variety under a polynomial map
Calling Sequence
Parameters
Description
Examples
PolynomialMapImage(F, PM, R, S)
PolynomialMapImage(F, H, PM, R, S)
PolynomialMapImage(CS, PM, R, S)
F
-
list of polynomials in R
PM
R
polynomial ring (source)
S
polynomial ring (target)
H
CS
constructible set
The command PolynomialMapImage(F, PM, R, S) returns a constructible set cs which is the image of the variety V⁡F under the polynomial map PM.
The command PolynomialMapImage(F, H, PM, R, S) returns a constructible set cs which is the image of the difference of the variety V⁡F by the variety V⁡H under the polynomial map PM.
The command PolynomialMapImage(CS, PM, R, S) returns a constructible set cs which is the image of the constructible set CS under the polynomial map PM.
Both rings R and S should be over the same base field.
The variable sets of R and S should be disjoint.
The number of polynomials in PM is equal to the number of variables of ring S.
This command is part of the RegularChains[ConstructibleSetTools] package, so it can be used in the form PolynomialMapImage(..) only after executing the command with(RegularChains[ConstructibleSetTools]). However, it can always be accessed through the long form of the command by using RegularChains[ConstructibleSetTools][PolynomialMapImage](..).
with⁡RegularChains:
with⁡ConstructibleSetTools:
The following example is related to the Whitney umbrella.
R≔PolynomialRing⁡u,v
R≔polynomial_ring
S≔PolynomialRing⁡x,y,z
S≔polynomial_ring
PM≔u⁢v,u,v2
cs≔PolynomialMapImage⁡,PM,R,S
cs≔constructible_set
cs≔MakePairwiseDisjoint⁡cs,S
Info⁡cs,S
x,y,1,x2−y2⁢z,y
See Also
ConstructibleSet
ConstructibleSetTools
Difference
MakePairwiseDisjoint
Projection
RegularChains
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