Upper triangular should be interpreted as getting only zero entries down below the key diagonal, which commences within the upper remaining corner. Example[edit] If a sq., invertible matrix has an LDU (factorization with all diagonal entries of L and U equivalent to one), then the factorization is unique.[5] In http://pinklingerie99.jiliblog.com/27190503/the-definitive-guide-to-how-t-u-an-l-b-d