« 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 alang-jabr presumably meant something like "restoration" or "completion" and seems to refer to the transposition ofwel subtracted terms to the other side http://www.drugoffice.gov.hk/gb/unigb/nl.wikipedia.org/wiki/Kwaliteit