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Jets > jetsProjection

jetsProjection -- canonical map between jets rings

Synopsis

Description

This function is provided by the package Jets. Generates an inclusion map from the order s into the order t jets of a (quotient of a) polynomial ring. Throws an error if t<s.

i1 : R=QQ[x,y]

o1 = R

o1 : PolynomialRing
i2 : f= jetsProjection(5,2,R)

o2 = map (QQ[x0, y0][x1, y1][x2, y2][x3, y3][x4, y4][x5, y5], QQ[x0, y0][x1, y1][x2, y2], {x2, y2, x1, y1, x0, y0})

o2 : RingMap QQ[x0, y0][x1, y1][x2, y2][x3, y3][x4, y4][x5, y5] <--- QQ[x0, y0][x1, y1][x2, y2]
i3 : use jets(2,R)

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

o3 : PolynomialRing
i4 : p= (x2 + 2*x1*y1 + x0*y2^2)

          2
o4 = x0*y2  + x2 + 2x1*y1

o4 : QQ[x0, y0][x1, y1][x2, y2]
i5 : f p

          2
o5 = x0*y2  + x2 + 2x1*y1

o5 : QQ[x0, y0][x1, y1][x2, y2][x3, y3][x4, y4][x5, y5]

Ways to use jetsProjection :

For the programmer

The object jetsProjection is a method function with options.