We compute the relative equations of a resonance degenerate K3 in case of k resonance. The first step consists in chooses a prime field which has a k-th root of unity. We then follow section 4 of the paper equations and syzygies of K3 carpets and unions of scrolls.
i1 : I = relativeEquations(4,4,3)
2 2 2 2
o1 = ideal (s*v - v v , t*v - v v , u v - 14s*u v + 13u v , t*u v - 14u v + 13u v , s*u - u u , t*u - u u , s*t*v v -
1 0 2 0 1 2 2 0 1 1 0 2 0 0 2 1 1 2 1 0 2 0 1 2 0 1
----------------------------------------------------------------------------------------------------------------------------
2 2
v , s*t*u v - 14s*t*u v + 13u v , s*t*u u - u )
2 1 0 0 1 2 2 0 1 2
ZZ
o1 : Ideal of --[s, t, u ..u , v ..v ]
61 0 2 0 2
|
i2 : betti I
0 1
o2 = total: 1 9
0: 1 .
1: . .
2: . 6
3: . 3
o2 : BettiTally
|
The object relativeEquations is a method function.