i1 : R = ZZ/101[x_0,x_1,x_2,y_0,y_1,Degrees=>{3:{1,0},2:{0,1}}]; |
i2 : X = projectiveVariety ideal random({2,1},R); o2 : ProjectiveVariety, surface in PP^2 x PP^1 |
i3 : Y = projectiveVariety ideal random({1,1},R); o3 : ProjectiveVariety, surface in PP^2 x PP^1 |
i4 : Z = X + Y; o4 : ProjectiveVariety, surface in PP^2 x PP^1 |
i5 : assert(Z - X == Y and Z - Y == X) |