# Special Functions for Ideals

Ideals of orders of quadratic fields inherit from ideals of orders of number fields (see Section [Ideals and Quotients](../NumberFieldsAndOrders/ideal.md#rngord-ideal) for the list of general functions and operations available). However there is also a correspondence between quadratic ideals and binary quadratic forms (see Chapter [Binary Quadratic Forms](../../LatticesQuadraticForms/BinaryQuadraticForms/index-binary-quadratic-forms.md#quadbin)). The following functions make use of that correspondence.

## `Content(I): RngQuadFracIdl -> RngQuadFracIdl`

The content of the ideal.

## `Conjugate(I): RngQuadFracIdl -> RngQuadFracIdl`

The conjugate of the ideal.

## `Discriminant(I): RngQuadFracIdl -> RngIntElt`

The discriminant of the quadratic form associated with $I$.

## `QuadraticForm(I): RngQuadFracIdl -> QuadBinElt`

The quadratic form associated with $I$.

## `Ideal(f): QuadBinElt -> RngQuadIdl`

The quadratic ideal with associated quadratic form $f$.

## `Reduction(I): RngQuadFracIdl -> RngQuadFracIdl`

The quadratic ideal with associated quadratic form which is a reduction of the quadratic form associated to $I$.