|
D.4.16.5 genus
Procedure from library normal.lib (see normal_lib).
- Return:
- an integer, the geometric genus p_g = p_a - delta of the projective
curve defined by i, where p_a is the arithmetic genus.
- Note:
- delta is the sum of all local delta-invariants of the singularities,
i.e. dim(R'/R), R' the normalization of the local ring R of the
singularity.
genus(I,"nor") uses the normalization to compute delta. Usually genus(I,"nor")
is slower than genus(I) but sometimes not.
genus(I,"pri") starts with a primary decompsition.
Example:
|