This method applies a formula given in Section 7 of the paper Special prime Fano fourfolds of degree 10 and index 2, obtaining the data required through the methods cycleClass, EulerCharacteristic and Euler (the option Algorithm allows you to select the method).
i1 : X = specialGushelMukaiFourfold "tau-quadric"; o1 : SpecialGushelMukaiFourfold (Gushel-Mukai fourfold containing a surface of degree 2 and sectional genus 0) |
i2 : time discriminant X -- used 2.54688 seconds o2 = 10 |