« 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 weet-jabr presumably meant something like "restoration" or "completion" and seems to refer to the transposition of subtracted terms to the other side https://zenwriting.net/tintights3/overwegingen-om-te-weten-over-wat-is-wrapfolie-wiki