« It Is not certain just what the terms al-jabr and muqabalah mean, but the usual interpretation is similar to that implied in the translation above. The word al-jabr presumably meant something like "restoration" or "completion" and seems to refer to the transposition of subtracted terms to the other side https://squareblogs.net/taiwanserver1/5-eenvoudige-technieken-voor-voorriut-geplakken-met-wrapfolie