(input/output) REAL or COMPLEX array,
shape with (AB,1) and (AB,2) ,
where is the number of subdiagonals or superdiagonals in the
band and is the order of and .
On entry, the upper (if UPLO = 'U') or lower
(if UPLO = 'L') triangle of matrix
in band storage. The diagonals of
are stored in the rows of AB so that the column of is
stored in the column of as follows:
On exit, the contents of AB are destroyed.