15th cent. edition of Reutlingen, Germany, the first production of Michael Greyff press, of Nicolaus Tinctoris Tinctor’s († 1498) commentary on the "Súmulas de lógica" of Pedro Hispano, current name of the Lisbon’s philosopher and physician Pedro Julião [ca. 1210-1277] who would become Pope John XXI in the last two years of his life. Full brown calf binding (not contemporary), with elaborate blind tooling on sides and spine.