Changing Coefficient Ring

The ChangeRing function enables the changing of the coefficient ring of an algebra or ideal.

ChangeRing(I, S) : AlgFr, Rng -> AlgFr
Given an ideal I of an algebra F=R[x1, ..., xn] of rank n with coefficient ring R, together with a ring S, construct the ideal J of the algebra Q=S[x1, ..., xn] obtained by coercing the coefficients of the elements of the basis of I into S. It is necessary that all elements of the old coefficient ring R can be automatically coerced into the new coefficient ring S. If R and S are fields and R is known to be a subfield of S and the current basis of I is a Gröbner basis, then the basis of J is marked automatically to be a Gröbner basis of J.
V2.28, 13 July 2023