A Question about Differential Ideals

The paper investigates the converse to the following theorem. Let R be a differential domain R which is finitely generated over a differential field F whose field of constants is algebraically closed of characteristic 0. If R has no proper nonzero differential ideals, then the quotient field, E, of R has no new constants. The converse is false, but a question was raised about the existence of a finitely generated extension of R within E which has no proper nonzero differential ideals when E has no new constants. This posted paper gives one example to show this is false and two limited positive results in Krull dimension one or two.