G = sub(F,R)
Constructs a polynomial system by attempting to map polynomials of a given system to a given ring.
i1 : R = QQ[x,y]; S := polySystem {x^2+y^2-6, 2*x^2-y} o2 = {-2} | x2+y2-6 | {-2} | 2x2-y | o2 : PolySystem
i3 : T := sub(S,CC[x,y]) o3 = {-2} | x2+y2-6 | {-2} | 2x2-y | o3 : PolySystem
i4 : ring T o4 = CC [x..y] 53 o4 : PolynomialRing