Fundamentals of Arithmetic; Fundamentals of Music

f = Munich codex 18480 (Tegernsee 480), 11th century, written both very beautifully and very diligently. However, many passages differ so much from the consensus of the remaining codices that they seem to reveal not the true words of Boethius, but the thoughts of a writer who was not unskilled. It is most similar to codex d.

l = Munich codex 14601 (Ratisbon, Emm. F, CIV), 12th century. In the first book, the similarity of this codex to d is so great that it might seem to have been copied from it, especially since it even received into the context things that had been corrected in d; in the second book, however, it is much more similar to codex b.

r = Munich codex 3517 (Augsburg civ. 17), 9th–10th century, neatly written. There was a greater knowledge of arithmetic in the writer than diligence in drawing letters, unless perhaps the reviser and the scribe of the work were different people. The codex appears to have been reviewed and corrected not long after it was written. It is similar to codex c and in part also to a. The titles of the chapters of the second book are similar to the titles of codex f. In some places, there are superfluous additions in it.

s = Munich codex 6405 (Frising. 205), 11th century, written very neatly. However, worms and usage have damaged the final folios to some extent. Many things that were written in red ink have either become paler or have vanished. It is most similar to codex a, yet not entirely so. In several places, there are found things that someone added of their own accord.

F = A fragment which Karl Friedrich Weber published from an eleventh-century codex at Kassel in 1847.

You may be led to distinguish two types of codices by the fourth chapter of the first book, where some codices (a, b) have the definition of an odd number in the middle of the chapter, while others (c, d, f, l, r, s) have it at the end. You will find better readings for the most part in c, d, f, l; but there are traces present that make it probable that these codices, at least those which I have collated and described above, flowed from one and the same source.