describe(MultiprojectiveVariety) -- describe a multi-projective variety

i1 : X = source graph rationalMap PP_(ZZ/65521)^(1,3);

o1 : ProjectiveVariety, threefold in PP^3 x PP^2

i2 : ? X

o2 = threefold in PP^3 x PP^2 cut out by 2 hypersurfaces of multi-degree
     (1,1)

i3 : describe X

o3 = ambient:.............. PP^3 x PP^2
     dim:.................. 3
     codim:................ 2
     degree:............... 10
     multidegree:.......... T_0^2+2*T_0*T_1+T_1^2
     generators:........... (1,1)^2 
     purity:............... true
     dim sing. l.:......... -1
     Segre embedding:...... map to PP^9 ⊂ PP^11

i4 : ? image segre X

o4 = 3-dimensional variety of degree 10 in PP^9 cut out by 18 hypersurfaces
     of degree 2