# ideal(MultiprojectiveVariety) -- the defining ideal of the variety

## Synopsis

• Function: ideal
• Usage:
ideal X
• Inputs:
• Outputs:
• an ideal, the defining ideal of $X$

## Description

 i1 : X = PP_QQ^({2,1},{1,3}); o1 : ProjectiveVariety, threefold in PP^2 x PP^3 i2 : ideal X 2 2 o2 = ideal (x1 - x1 x1 , x1 x1 - x1 x1 , x1 - x1 x1 ) 2 1 3 1 2 0 3 1 0 2 o2 : Ideal of QQ[x0 ..x0 , x1 ..x1 ] 0 2 0 3