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7.7.19.0. WeylClosure
Procedure from library dmodloc.lib (see dmodloc_lib).
- Usage:
- WeylClosure(I); I an ideal
- Assume:
- The basering is the n-th Weyl algebra W over a field of
characteristic 0 and for all 1<=i<=n the identity
var(i+n)*var(i)=var(i)*var(i+1)+1 holds, i.e. the sequence of
variables is given by x(1),...,x(n),D(1),...,D(n), where D(i) is the
differential operator belonging to x(i).
Moreover, assume that the holonomic rank of W/I is finite.
- Return:
- ideal, the Weyl closure of I
- Remarks:
- The Weyl closure of a left ideal I in the Weyl algebra W is defined to
be the intersection of I regarded as left ideal in the rational Weyl
algebra K(x(1..n))<D(1..n)> with the polynomial Weyl algebra W.
Reference: (Tsa), Algorithm 2.2.4
- Note:
- If printlevel=1, progress debug messages will be printed,
if printlevel>=2, all the debug messages will be printed.
Example:
See also:
WeylClosure1.
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