Thanks for your quick reply! I understand how to make this work for a simple expression as in your example, but can you please explain how to incorporate this into the system of solutions? Doing so directly (with sols rather than ex in the applyrule call) does not work as intended.

Thanks for your quick reply! I understand how to make this work for a simple expression as in your example, but can you please explain how to incorporate this into the system of solutions? Doing so directly (with sols rather than ex in the applyrule call) does not work as intended.