"It would be rather pointless and confusing to retain in these books information that was incorrect or defective or inaccurate. That is to say, books on science and mathematics would naturally be propagated accretively, with the addition of numerous anonymous updates, though no one maintained a revision history. Certainly Arab authors in Baghdad, for example, were actively disinterested in verbatim translations, but were interested rather more in useful paraphrases and creative reworking."