REGULA FALSI apud Philozophantes Augmenti et Decrementi appellata, omnium Regulis Algobre demptis optima. FIRST EDITION, 20 leaves: A8, B-C6, gothic types, 33 lines, underlines and one MS. initial in red, (wormholes affecting text), calf by W. Parnell of Hedon (defective), [C 5085; BMC III, 640; Goff R-119; Günthe 1468; Klebs 843.1], chancery 4to, Leipzig, Martin Landsberg, [ca. 1495]. AN ARITHMETICAL INCUNABLE OF CONSIDERABLE RARITY. It is bound together with three manuscripts, including Virginia, a Tragedy, 18th-century, and two printed books, one a 16th-century book from Colbert's library.