x_R := PolynomialAlgebra( IntegerRing() ); x_x := Generator(x_R, 1); x_O := MaximalOrder(x_x^2 - 18); x_a := Element(x_O, [0,1]); x_Ox := PolynomialAlgebra( x_O ); x_x := Generator(x_Ox, 1); x_OO := MaximalOrder( x_x^3 - 27*x_a ); x_I := Factorization( 3*x_OO )[1][1]; x_M := Module(x_I); xL := List( [1..3], i->Generator(x_M, i) );