A ** K
This methods makes a new hyperplane arrangement by changing the coefficient ring of the underlying ring.
i1 : R = ZZ[x,y];
i2 : A = arrangement{x,y,x-y} o2 = {x, y, x - y} o2 : Hyperplane Arrangement
i3 : A' = A ** QQ o3 = {x, y, x - y} o3 : Hyperplane Arrangement
i4 : ring A' o4 = QQ[x..y] o4 : PolynomialRing
i5 : assert(R =!= ring A')