Description
If
R is a polynomial ring, then the coefficient ring is the base ring from which the coefficients are drawn. If
R is constructed from a polynomial ring as a quotient ring or a fraction ring or a sequence of such operations, then the original coefficient ring is returned.
i1 : coefficientRing(ZZ/101[a][b])
ZZ
o1 = [a]
101
o1 : PolynomialRing

i2 : ultimate(coefficientRing,ZZ/101[a][b])
ZZ
o2 = 
101
o2 : QuotientRing
