Where is the subject boundary between the end of Hajr and the next book?

Kitab al-Hajr: Creditors After Release and Final Rulings

• Equal ranking of the unpaid seller closes Hajr; Kitab al-Iqrar follows
• Kitab al-Sawm follows immediately after wrongdoing
• Kitab al-Talaq immediately follows attendance
• Kitab al-Hajj follows with no further ruling