JJ -- scripted functor associated with jets

i1 : R = QQ[x,y]

o1 = R

o1 : PolynomialRing

i2 : I = ideal(y^2-x^3)

              3    2
o2 = ideal(- x  + y )

o2 : Ideal of R

i3 : JJ_2 R

o3 = QQ[x0, y0][x1, y1][x2, y2]

o3 : PolynomialRing

i4 : JJ_2 I

                 2                    2     2       2                 3  
o4 = ideal (- 3x0 x2 + 2y0*y2 - 3x0*x1  + y1 , - 3x0 x1 + 2y0*y1, - x0  +
     ------------------------------------------------------------------------
       2
     y0 )

o4 : Ideal of QQ[x0, y0][x1, y1][x2, y2]