RationalMap _* -- direct image via a rational map

Synopsis

Operator: _*
Usage:

phi_* I
Inputs:
- phi, a rational map, I a homogeneous ideal in the coordinate ring of the source of phi
Outputs:
- an ideal, the ideal of the closure of the direct image of V(I) via phi

In most cases this is equivalent to phi I, which is faster but may not take into account other representations of the map.