RegularChains[FastArithmeticTools]
NormalizeRegularChainDim0
normalize a zero-dimensional regular chain
Calling Sequence
Parameters
Description
Examples
NormalizeRegularChainDim0(rc, R)
R
-
polynomial ring
rc
a regular chain of R
Returns a normalized regular chain generating the same ideal as rc.
rc is a zero-dimensional non-empty regular chain.
Moreover R must have a prime characteristic p such that FFT-based polynomial arithmetic can be used for this actual computation. The higher the degrees of f and rc are, the larger must be e such that 2e divides p−1. If the degree of f or rc is too large, then an error is raised.
with⁡RegularChains:
with⁡FastArithmeticTools:
with⁡ChainTools:
variables≔x,y,z:p≔957349889:
sys≔5⁢y4−3,−20⁢x+y−z,−x5+y5−3⁢y−1:
R≔PolynomialRing⁡variables,p
R≔polynomial_ring
We solve a system in 3 variables and 3 unknowns
lrc≔Triangularize⁡sys,R
lrc≔regular_chain
Its triangular decomposition consists of only one regular chain
rc≔lrc1
rc≔regular_chain
Equations⁡rc,R
z12+94127136⁢z8+691135635⁢z7+676458799⁢z4+195425386⁢z3+326553470⁢z2+574327669⁢x+27352854⁢z13+673373922⁢z9+410681381⁢z8+817312291⁢z5+308837227⁢z4+32655347⁢z3+116876413⁢z+880926729,z12+94127136⁢z8+691135635⁢z7+676458799⁢z4+195425386⁢z3+326553470⁢z2+574327669⁢y+547057079⁢z13+927802747⁢z9+821042762⁢z8+352188797⁢z5+237219820⁢z4+326553470⁢z3+805850702⁢z+386236578,z20+957349886⁢z16+944549889⁢z15+886639826⁢z12+458149889⁢z11+156173647⁢z10+568152312⁢z8+120112423⁢z7+434195336⁢z6+398220483⁢z5+536874419⁢z4+604689895⁢z3+446611758⁢z2+237311560⁢z+665813406
Each initial is not equal to 1, hence this regular chain is not normalized
map⁡Initial,Equations⁡rc,R,R
z12+94127136⁢z8+691135635⁢z7+676458799⁢z4+195425386⁢z3+326553470⁢z2+574327669,z12+94127136⁢z8+691135635⁢z7+676458799⁢z4+195425386⁢z3+326553470⁢z2+574327669,1
We compute here a regular chain which is normalized and which describes the same solution as the previous one
nrc≔NormalizeRegularChainDim0⁡rc,R
nrc≔regular_chain
We check that it is normalized
Equations⁡nrc,R:map⁡Initial,Equations⁡nrc,R,R
1,1,1
We check that the two regular chains describe the set of solutions
EqualSaturatedIdeals⁡rc,nrc,R
true
See Also
NormalForm
NormalFormDim0
NormalizePolynomialDim0
ReduceCoefficientsDim0
RegularChains
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