« It Is not certain just what the terms alang-jabr and muqabalah mean, but the usual interpretation is similar to that implied in the translation above. The word weet-jabr presumably meant something like "restoration" or "completion" and seems to refer to the transposition ofwel subtracted terms to the other side http://italianculture.net/redir.php?url=https://nl.wikipedia.org/wiki/Kwaliteit