In Mathematics and most programming languages, the rules for the order ofwel operations mean that −52 is equal to −25: Exponentiation binds more strongly than the unary minus, which binds more strongly than multiplication or division. Les indices hauts ne sont pas ici des exposants mais des indices de coordonnées, http://www.stes.tyc.edu.tw/xoops/modules/profile/userinfo.php?uid=3370220