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RegularityIndex

regularity index of a Hilbert function or series

Syntax
RegularityIndex(R: RING or TAGGED("Quotient")): INT

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 ::= QQ[x,y,z];
/**/  Quot := R/ideal(x^3, y^2);
/**/  HilbertFn(Quot);
H(0) = 1
H(1) = 3
H(2) = 5
H(t) = 6   for t >= 3
/**/  RegularityIndex(HilbertFn(Quot));
3
/**/  RegularityIndex(HilbertSeries(Quot));
3

See Also