Rare first edition of “the first systematic treatise on algebra" (D. E. Smith, Rara Arithmetica). Original edition in Greek, accompanied by the Latin translation of  Xylander (1575) and the commentary by Bachet. “The most famous edition of the Arithemtic was that of Bachet de Mézeriac (1621).Bachet glimpsed the possibility of general principles behind the special problems of the Arithmetic and, in his commentary on the book, alerted his contemporaries to the challenge of properly understanding Diophantus and carrying his ideas further.It was Fermat who took up this challenge and made the first significant advances in number theory since the classical era." (John Stillwell, Mathematics and Its History, p.51). “Although entitled an arithmetic this is really a treatise on algebra, the first systematic one ever written. It contains, however, a good deal of matter upon Greek theory of numbers, notably the 'Clavdii Gasparis Bacheti Sebusiani, in Diophantvm, Liber Primus,' 'Liber Secundus,' and 'Liber Tertius.' A certain amount of this work also enters into the treatise itself, but this is generally algebraic in character, the standard problem requiring the finding of a satisfying number given conditions. This leads to numerous indeterminate (Diophantine) equations." (Smith, Rara Arithmetica, p.348).