How is a shared courtyard (sahn) divided between the owner of the upper story (ceiling/floor) of a khan and the owner of the lower story, given that the upper owner has a staircase located within the khan's courtyard?

Primary text

If the disagreement concerns the courtyard when the upper owner has a staircase located within the courtyard, the portion from the staircase to the khan's door is shared between them. Beyond that point towards the end of the khan's courtyard, two secondary views apply: either that section belongs exclusively to the lower owner, or it is shared between them. If the staircase is located at the very end of the courtyard, the entire courtyard is shared between them due to the established possession and use by both parties.