a ring, the ring R[It] ⊗ R/I of the normal cone of I
Description
The normal cone of an ideal I⊂ R is the ring R/I ⊕ I/I^{2} ⊕..., also called the associated graded ring of R with respect to I. If S is the Rees algebra of I, then this ring is isomorphic to S/IS, which is how it is computed here.
See also
reesAlgebra -- Compute the defining ideal of the Rees Algebra