This is a Persian work in 30 chapters that Ṭūsī tells us he wrote for his students. It is quite different in organization (and to some extent content) from the Zubdat al-idrāk fī al-hayʾa, which may or may not be by Ṭūsī. Because the two works are often confused, listed manuscripts need to be checked. Based on a reading by Fateme Savadi of the colophon of MS Ahmet III 3455, f. 68b, the work can be dated to the last part of Rabīʿ al-ākhir, 666 H (Savadi, p. 28, n. 94: https://doi.org/10.82308/33550).