Ṭūsī appended this exposition in a supplement to his Risālah-i Mu`īniyya. Various titles: Ḥall-i mushkilāt-i Mu`īniyya; Sharḥ-i Mu`īniyya or Dhayl-i Mu`īniyya (the solution of Difficulties, A commentary of an Appendix for the Mu`īniyya); dedicated to Mu`īn al-Dīn Shams, son of Nāṣir al-Dīn Muḥtasham, the Ismā`īlī governor of Qūhistān in Eastern Iran 