CoCoA:RegularityIndex

RegularityIndex

regularity index of a Hilbert function or series

Description

This function computes the regularity index of a Hilbert function.

The input might be expressed as a Hilbert function or as the

corresponding Hilbert series (computed with standard weights).

Example

  Use R ::= Q[x,y,z];
  Quot := R/Ideal(x^3, y^2);
  HilbertFn(Quot);
H(0) = 1
H(1) = 3
H(2) = 6
H(3) = 10
H(4) = 15
H(t) = 7t - 14   for t >= 5
-------------------------------
  RegularityIndex(Hilbert(Quot));
3
-------------------------------
  RegularityIndex(Poincare(Quot));
3
-------------------------------

Syntax

RegularityIndex(R:RING or TAGGED(<quotes>Quotient</quotes>)):INT

Hilbert

HilbertFn

HilbertSeries

Poincare

   <type>hilbert</type>