Arguments

DL

(input/output) REAL or COMPLEX array, shape $(:)$ with $size({\bf DL}) = n-1$, where $n$ is the order of A.
On entry, the subdiagonal of $A$.
On exit, the $n-2$ elements of the second superdiagonal of $U$ in ${\bf DL}_1, \cdots , {\bf DL}_{n-2}$.

D

(input/output) REAL or COMPLEX array, shape $(:)$ with $size({\bf D}) = n$.
On entry, the diagonal of $A$.
On exit, the diagonal of $U$.

DU

(input/output) REAL or COMPLEX array, shape $(:)$ with $size({\bf DL}) = n-1$.
On entry, the superdiagonal of $A$.
On exit, the first superdiagonal of $U$.

B

(input/output) REAL or COMPLEX array, shape $(:,:)$ with $size({\bf B},1) = n$ or shape $(:)$ with $size({\bf B}) = n$.
On entry, the matrix $B$.
On exit, the solution matrix $X$.

INFO

Optional (output) INTEGER


If ${\bf INFO}$ is not present and an error occurs, then the program is terminated with an error message.

References: [1] and [17,9,20].