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MultiprojectiveVarieties :: segre(MultiprojectiveVariety)

segre(MultiprojectiveVariety) -- the Segre embedding of the variety

Synopsis

Description

i1 : X = projectiveVariety ideal random({2,1},ZZ/101[x_0,x_1,x_2,y_0,y_1,Degrees=>{3:{1,0},2:{0,1}}]);

o1 : ProjectiveVariety, surface in PP^2 x PP^1
i2 : segre X

o2 = -- rational map --
                                 ZZ                      ZZ
     source: subvariety of Proj(---[x , x , x ]) x Proj(---[y , y ]) defined by
                                101  0   1   2          101  0   1
             {
               2                  2                            2        2                 2                           2
              x y  + 24x x y  + 8x y  + 5x x y  - 34x x y  + 3x y  + 49x y  + 3x x y  + 3x y  + 5x x y  - 43x x y  - x y
               0 0      0 1 0     1 0     0 2 0      1 2 0     2 0      0 1     0 1 1     1 1     0 2 1      1 2 1    2 1
             }
                   ZZ
     target: Proj(---[y , y , y , y , y , y ])
                  101  0   1   2   3   4   5
     defining forms: {
                      x y ,
                       0 0
                      
                      x y ,
                       0 1
                      
                      x y ,
                       1 0
                      
                      x y ,
                       1 1
                      
                      x y ,
                       2 0
                      
                      x y
                       2 1
                     }

o2 : MultihomogeneousRationalMap (rational map from surface in PP^2 x PP^1 to PP^5)

See also