i1 : isAffineRing CC o1 = true
i2 : isAffineRing (ZZ[a,b,c,d]) o2 = false
i3 : isAffineRing (ZZ/101[a,b,c,d]) o3 = true
i4 : isAffineRing (ZZ/2[x,y,z]/(x^2-y*z)) o4 = true
i5 : isAffineRing (QQ[x,dx, WeylAlgebra => {x => dx}]) o5 = true