i1 : use Grass(0,5,ZZ/33331); |
i2 : -- quintic del Pezzo surface S = ideal(p_2*p_4-p_1*p_5, p_0*p_4-p_1*p_5-p_3*p_5+p_4*p_5, p_2*p_3-p_0*p_5, p_1*p_3-p_1*p_5-p_3*p_5+p_4*p_5, p_0*p_1-p_1*p_2-p_0*p_5+p_1*p_5); ZZ o2 : Ideal of -----[p ..p ] 33331 0 5 |
i3 : X = specialCubicFourfold(S,NumNodes=>0); o3 : SpecialCubicFourfold (Cubic fourfold containing a surface of degree 5 and sectional genus 1) |
i4 : discriminant X o4 = 14 |
Some random cubic fourfolds can also be obtained by passing strings. For instance, an object as above is also given as follows.
i5 : specialCubicFourfold("quintic del Pezzo surface"); o5 : SpecialCubicFourfold (Cubic fourfold containing a surface of degree 5 and sectional genus 1) |