Ideals

Ideal(S, gens) : AlgEtQOrd, SeqEnum -> AlgEtQIdl
Creates an ideal of the order S, generated by the elements of gens.
Ideal(S, idls) : AlgEtQOrd, Tup -> AlgEtQIdl
Given an order S which is a product of orders Si in the number fields generating Algebra(S), and a tuple of ideals Ii of Si, returns the S-ideal corresponding to the direct sum of the Ii.
Ideal(S, gen) : AlgEtQOrd, Any -> AlgEtQIdl
S * gen : AlgEtQOrd, AlgEtQElt -> AlgEtQIdl
S * gen : AlgEtQOrd, RngIntElt -> AlgEtQIdl
S * gen : AlgEtQOrd, FldRatElt -> AlgEtQIdl
gen * S : AlgEtQElt, AlgEtQOrd -> AlgEtQIdl
gen * S : RngIntElt, AlgEtQOrd -> AlgEtQIdl
gen * S : FldRatElt, AlgEtQOrd -> AlgEtQIdl
Creates an ideal of S, generated by gen.
T !! I : AlgEtQOrd, AlgEtQIdl -> AlgEtQIdl
Given an S-ideal I and an order T, returns the extension IT as a T-ideal. Note that if T is a subset of S, then IT=I.
Algebra(I) : AlgEtQIdl -> AlgEtQ
Returns the étale algebra in which the ideal I lives.
Order(I) : AlgEtQIdl -> AlgEtQOrd
Returns the order of definition of the ideal I.
ZBasis(I) : AlgEtQIdl -> SeqEnum[AlgEtQElt]
Returns a Z-basis of the ideal I.
Generators(I) : AlgEtQIdl -> SeqEnum[AlgEtQElt]
Returns the generators of the ideal I.
I eq J : AlgEtQIdl, AlgEtQIdl -> BoolElt
I ne J : AlgEtQIdl, AlgEtQIdl -> BoolElt
Returns whether the ideals I and J are equal, respectively not equal.
I eq S : AlgEtQIdl, AlgEtQOrd -> BoolElt
S eq I : AlgEtQOrd, AlgEtQIdl -> BoolElt
Return whether I is equal to S when I is an ideal of S.
AbsoluteCoordinates(seq, I) : SeqEnum[AlgEtQElt], AlgEtQIdl -> SeqEnum
Returns the coordinates of the elements in seq with respect to the internal fixed basis. The basis used is returned by AbsoluteBasis.
x in I : AlgEtQElt, AlgEtQIdl -> BoolElt
x in I : RngIntElt, AlgEtQIdl -> BoolElt
x in I : FldRatElt, AlgEtQIdl -> BoolElt
Returns whether the element x is in the ideal I.
S subset I : AlgEtQOrd, AlgEtQIdl -> BoolElt
Given an ideal I of an order S, return whether S ⊆I.
I subset S : AlgEtQIdl, AlgEtQOrd -> BoolElt
Given an ideal I of an order S, return whether I ⊆S.
I1 subset I2 : AlgEtQIdl, AlgEtQIdl -> BoolElt
Checks if the ideal I1 is inside the ideal I2. The ideals need to be fractional.
Index(T) : AlgEtQIdl -> FldRatElt
Given an ideal T computes its index with respect to the basis of the algebra of T as a free Q-module.
Index(J, I) : AlgEtQIdl, AlgEtQIdl -> Any
Given fractional ideals J and I defined over the same order returns [J:I] = [J:J ∩I]/[I : J ∩I].
Index(S, I) : AlgEtQOrd, AlgEtQIdl -> Any
Given an ideal I of an order S returns [S:I] = [S:S ∩I]/[I : S ∩I].
OneIdeal(S) : AlgEtQOrd -> AlgEtQIdl
Given an order S returns the ideal 1 * S which will be cached.
Conductor(O) : AlgEtQOrd -> AlgEtQOrdIdl
Computes the conductor of an order O, defined as the colon ideal (O:OK), where OK is the maximal order of the algebra.
I + J : AlgEtQIdl, AlgEtQIdl -> AlgEtQIdl
Returns the sum of two ideals.
I * J : AlgEtQIdl, AlgEtQIdl -> AlgEtQIdl
Product of two ideals.
I * x : AlgEtQIdl, AlgEtQElt -> AlgEtQIdl
I * x : AlgEtQIdl, RngIntElt -> AlgEtQIdl
I * x : AlgEtQIdl, FldRatElt -> AlgEtQIdl
x * I : AlgEtQElt, AlgEtQIdl -> AlgEtQIdl
x * I : RngIntElt, AlgEtQIdl -> AlgEtQIdl
x * I : FldRatElt, AlgEtQIdl -> AlgEtQIdl
Returns x * I.
I ^ n : AlgEtQIdl, RngIntElt) -> AlgEtQIdl
Returns the nth power of an ideal.
I meet S : AlgEtQIdl, AlgEtQOrd -> AlgEtQIdl
S meet I : AlgEtQOrd, AlgEtQIdl -> AlgEtQIdl
Given an ideal I of S, return S ∩I.
I meet J : AlgEtQIdl, AlgEtQIdl -> AlgEtQIdl
Given ideals I and J, return J ∩I.
&+ seq : SeqEnum[AlgEtQIdl] -> AlgEtQIdl
Returns the sum of the fractional ideals in the sequence.
ColonIdeal(I, J) : AlgEtQIdl, AlgEtQIdl -> AlgEtQIdl
Computes the colon ideal (I:J) (as an O-ideal) of two O-ideals, which is the set of elements x of the algebra such that x .J ⊂I.
ColonIdeal(O, J) : AlgEtQOrd, AlgEtQIdl -> AlgEtQIdl
Computes the colon ideal (1 .O:J) (as an O-ideal).
ColonIdeal(I, O) : AlgEtQIdl, AlgEtQOrd -> AlgEtQIdl
Computes the colon ideal (I:1 .O) (as an O-ideal).
IsInvertible(I) : AlgEtQIdl -> BoolElt
Checks if the ideal I is invertible in its order of definition O.
Inverse(I) : AlgEtQIdl -> AlgEtQIdl
Computes the inverse of an invertible ideal I.
MultiplicatorRing(I) : AlgEtQIdl -> AlgEtQOrd
Given a fractional ideal I computes its multiplicator ring (I:I).
IsProductOfIdeals(I) : AlgEtQIdl -> BoolElt, Tup
Return if the ideal I is a product of ideals in the number fields defining the algebra. If so, it returns also the sequence of these ideals (in the appropriate orders). Note: we require Order(I) to be MultiplicatorRing(I).
Random(I, bd) : AlgEtQIdl, RngIntElt -> AlgEtQElt
    ZeroDivisorsAllowed: BoolElt        Default: false
Returns a random element of the ideal I. The coefficients are bounded by the positive integer bd. One can allow zero-divisors using the optional parameter ZeroDivisorsAllowed, which by default is set to false.
Random(I) : AlgEtQIdl -> AlgEtQElt
    CoeffRange: RngIntElt               Default: 3
    ZeroDivisorsAllowed: BoolElt        Default: false
Returns a random (small coefficient) element of the ideal I. The range of the random coefficients can be increased by giving the optional parameter CoeffRange. One can allow zero-divisors using the optional parameter ZeroDivisorsAllowed, which by default is set to false.
IsCoprime(I, J) : AlgEtQIdl, AlgEtQIdl -> BoolElt
Given two integral ideals I and J of an order S, returns whether I + J=R.
IsIntegral(I) : AlgEtQIdl -> BoolElt
Returns whether the ideal I of S is integral, that is I ⊆S.
MakeIntegral(I) : AlgEtQIdl -> AlgEtQIdl, RngIntElt
Given a fractional S ideal I, returns the ideal d .I, d when d is the smallest integer such that d .I is integral in S. Compare with SmallRepresentative.
MinimalInteger(I) : AlgEtQIdl -> RngIntElt
Returns the smallest integer contained in the ideal I.
CoprimeRepresentative(I, J) : AlgEtQIdl, AlgEtQIdl -> AlgEtQElt, AlgEtQIdl
Returns an element x such that x .I is an integral ideal coprime with J, togheter with the product x .I. The first ideal must be invertible and the second should be integral.
ZBasisLLL(~S) : AlgEtQOrd ->
ZBasisLLL(~S) : AlgEtQIdl ->
A procedure that replaces the ZBasis with an LLL-reduced one. Note: the attribute inclusion matrix, which depends on the Z-Basis is modified as well.
V2.29, 21 October 2025