Home Online Manual
Top
Back: PPolyN
Forward: graal_lib
FastBack:
FastForward:
Up: goettsche_lib
Top: Singular Manual
Contents: Table of Contents
Index: Index
About: About this document

D.15.14.8 BettiNumsN

Procedure from library goettsche.lib (see goettsche_lib).

Usage:
BettiNumsN(q, m, n); q, m, n integers

Return:
list of integers

Purpose:
computes the Betti numbers of the moduli space
of Kronecker modules N(q; m, n)

Note:
if m and n are not coprime, the result does not necessary make sense

Example:
 
LIB "goettsche.lib";
ring r=0, (t), dp;
// get the Betti numbers of N(3; 2, 3)
print( BettiNumsN(3, 2, 3) );
==> [1]:
==>    1
==> [2]:
==>    0
==> [3]:
==>    1
==> [4]:
==>    0
==> [5]:
==>    3
==> [6]:
==>    0
==> [7]:
==>    3
==> [8]:
==>    0
==> [9]:
==>    3
==> [10]:
==>    0
==> [11]:
==>    1
==> [12]:
==>    0
==> [13]:
==>    1