Byzantinische Mathematik im 15. Jahrhundert. Codex Vindobonensis philologicus graecus 65

The anonymous Codex Wien, Austrian National Library, phil. gr. 65, is one of the most important late Byzantine mathematical manuscripts. Following the author's 2014 publication on the arithmetic, this is an annotated edition of folios IIv-9v, which, in the manuscript's current binding, precede the beginning of the arithmetic book. The content deals with perfect numbers in various interpretations and with topics for the (later!) addition of chapters to the arithmetic book from the core text (lattice multiplication, rule of nines, mental multiplication). The text is of paramount importance for fundamentally new insights, especially regarding the structure of the codex and its authorship. Therefore, the codex is bound incorrectly, and the Aristotle commentator and Metropolitan of Mytilene Leon Magentenos (first half of the 14th century), as incorrectly stated in the specialist literature on this manuscript, is to be excluded as a co-author.