x_R := PolynomialAlgebra( IntegerRing() ); x_x := Generator(x_R, 1); x_F := NumberField(x_x^2 - 18); x_a := Element(x_F, [0,1] ); x_Fx := PolynomialAlgebra( x_F ); x_x := Generator(x_Fx, 1); x_FF := NumberField( x_x^3 - 27*x_a ); AbsoluteField(x_FF);