# ApCoCoA-1:Weyl.CharI

## Weyl.CharI

Computes the characteristic ideal of a `D`-ideal I in Weyl algebra `A_n`.

### Syntax

Weyl.CharI(I:IDEAL):IDEAL

### Description

*Please note:* The function(s) explained on this page is/are using the *ApCoCoAServer*. You will have to start the ApCoCoAServer in order to use it/them.

This function omputes the characteristic ideal, InIw(I,[0,e]), of a D-ideal I the Weyl algebra D. This is an ideal in the commutative polynomial ring in 2n variables. The zeroset of this ideal in affine 2n-space is called characteristic variety of I. Due to limitations in CoCoA4, [0,e] is replaced by [1,10000]. This will be modified later in the future release with CoCoA5.

This function computes a Groebner Basis for an Ideal `I = (f_1,f_2, ..., f_r)` where every generator `f_i` should be a Weyl polynomial in Normal form.

@param

*I*An ideal in the Weyl algebra.@return Characteristic ideal of the given ideal.

#### Example

#### Example

### See also

Introduction to Groebner Basis in CoCoA