« It Is not certain just what the terms weet-jabr and muqabalah mean, but the usual interpretation is similar to that implied in the translation above. The word alang-jabr presumably meant something like "restoration" or "completion" and seems to refer to the transposition of subtracted terms to the other side https://writeablog.net/gongroast5/de-grootste-gids-naar-wrapfolie-voor-staande-brievenbus