x_Qx:=PolynomialAlgebra(Q); x_Qxy := PolynomialAlgebra(x_Qx); x_x := x_Qx.1; x_y := x_Qxy.1; x_f:=x_y^2 +x_x^3 + x_x + 1; x_F:=FunctionField(x_f); x_o:=MaximalOrderFinite(x_F); x_I:=Element(x_o,[1,1/5])*x_o; Denominator(x_I);