Book of history

According to Vasiliev (1911: 562 n. 1), Yahya ibn Adi the Grammarian is not to be confused with Abu Zakariya Yahya ibn Adi (893-974), the Syrian Orthodox theologian, philosopher and translator linked to the so-called 'Aristotelian school of Baghdad'. The absence of any work of history or grammar among the writings ascribed to Abu Zakariya Yahya ibn Adi seems to confirm Vasiliev's assumption. The passage mentioning Yahya ibn Adi is damaged in the manuscript of the 'Kitāb al-'unwān'. Vasiliev and Pirrone propose two significantly different reconstructions. Vasiliev implies that Yhaya's work concerned somehow a certain Constant (Vasiliev 1911: 562: "Jachya, fils d'Adiya, le grammairien, dit dans sa chronique qu'il a faite sur ... de Constant (?); il commence et il dit: Adam gouverna le monde pendant 230 ans; Seth gouverna le monde pendant 205 ans"). Pirrone, instead, reads 'Constant' as the name of a source of Yahya's (Pirrone 2013: 296: "Yaḥyà Ibn 'Adī, il Grammatico, nel suo Kitāb al-ta'rīkh da lui composto nell'eremo racconta: Qusṭanṭūs comincia con il dire 'Adamo governò il mondo 230 anni; Set governò il mondo 205 anni…'"): see the lemma on Constantius the chronicler. Both reconstructions are equally hypothetical and questionable, therefore the only pieces of information that can be certainly gathered about this source of Agapius are the author's name and the title of the work.