Let D be an Sn symmetric Q-divisor on M0,n. This function reduces a symmetric divisor D by the gcd of its coefficients in the standard basis. This gives a canonical representative of each nonzero ray in Pic(M0,n)QSn.
i1 : D=symmetricDivisorM0nbar(6,288*B_2+144*B_3) o1 = 288*B + 144*B 2 3 o1 : S_6-symmetric divisor on M-0-6-bar |
i2 : scale(D) o2 = 2*B + B 2 3 o2 : S_6-symmetric divisor on M-0-6-bar |