i1 : X = specialCubicFourfold "quartic scroll";
o1 : ProjectiveVariety, cubic fourfold containing a surface of degree 4 and sectional genus 0

i2 : describe X
o2 = Special cubic fourfold of discriminant 14
containing a (smooth) surface of degree 4 and sectional genus 0
cut out by 6 hypersurfaces of degree 2

i3 : time U' = associatedK3surface X;
 used 4.08909 seconds
o3 : ProjectiveVariety, K3 surface associated to X

i4 : (mu,U,C,f) = building U';

i5 : ? mu
o5 = multirational map consisting of one single rational map
source variety: PP^5
target variety: hypersurface in PP^5 defined by a form of degree 2
dominance: true

i6 : ? U
o6 = surface in PP^5 cut out by 7 hypersurfaces of degrees 2^1 3^6

i7 : last C
o7 = curve in PP^5 cut out by 4 hypersurfaces of degrees 1^3 2^1
o7 : ProjectiveVariety, curve in PP^5 (subvariety of codimension 1 in U)

i8 : assert(image f == U')
