« 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://sparktv.net/post/277912_https-foliemolie-nl-https-nl-wikipedia-org-wiki-kwaliteit-https-foliemolie-nl-do.html