Procedure from library gmssing.lib (see gmssing_lib).
Usage:
sppairs(t); poly t
Assume:
characteristic 0; local degree ordering;
isolated critical point 0 of t
Return:
list spp; spectral pairs of t
ideal spp[1];
number spp[1][i]; V-filtration index of i-th spectral pair
intvec spp[2];
int spp[2][i]; weight filtration index of i-th spectral pair
intvec spp[3];
int spp[3][i]; multiplicity of i-th spectral pair