Kitāb fī annahū idhā waqa`a khaṭṭ mustaqīm `alā khaṭṭayn mustaqīmayn fa-sayyara al-zāwiyatayn allatayn fī jiha wāḥida aqall min qā’imatayn fa-‘inna al-khaṭṭayn iltaqayā idhā ukhrijā fī tilka al-jihā = Maqāla fī burhān al-muṣādira al-mashhūra min Uqlīdis - under the first title - Istanbul (SM AS 4832/9)