Constructs a curve with the function idealOfNodalCurve and computes the Artinian reduction of I. Afterwards the function "koszulMap" from the M2 package extrasForTheKernel is used to compute the critical Koszul map.
i1 : (k,g,n)=(4,8,1000); |
i2 : I=idealOfNodalCurve(k,g,n);
ZZ
o2 : Ideal of ----[t , t , t , t , t , t , t , t ]
1009 0 1 2 3 4 5 6 7
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i3 : A=criticalKoszulMap(I);
ZZ 120 ZZ 90
o3 : Matrix (----) <--- (----)
1009 1009
|
i4 : m=ceiling((g-1)/2); |
i5 : rank(ker A)- binomial(g-2,m+1) o5 = 4 |
i6 : loadPackage("extrasForTheKernel",Reload=>true);
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i7 : (Tred,Ired)=artinianReduction(I); |
i8 : betti res Ired
0 1 2 3 4 5 6
o8 = total: 1 15 39 50 39 15 1
0: 1 . . . . . .
1: . 15 35 25 4 . .
2: . . 4 25 35 15 .
3: . . . . . . 1
o8 : BettiTally
|