When is the pre-emptive prostration (sujud al-qabli) and the post-emptive prostration (sujud al-ba'di) due? Thank you.

Scholars have differed regarding the timing of the prostration of forgetfulness (sujud al-sahw). Some said it should all be before the salutation (taslim), while others said it should all be after the salutation. Still others provided a detailed explanation, which is the more valid opinion adopted by Ibn Taymiyyah: prostration for a deficiency should be before the salutation, and for an addition, it should be after the salutation. Similarly, doubt accompanied by investigation should be after the salutation, whereas doubt accompanied by building upon certainty should be before the salutation.