```    Program f07vhfe

!     F07VHF Example Program Text

!     Mark 27.0 Release. NAG Copyright 2019.

!     .. Use Statements ..
Use nag_library, Only: dtbrfs, dtbtrs, nag_wp, x04caf
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Integer, Parameter               :: nin = 5, nout = 6
Character (1), Parameter         :: diag = 'N', trans = 'N'
!     .. Local Scalars ..
Integer                          :: i, ifail, info, j, kd, ldab, ldb,    &
ldx, n, nrhs
Character (1)                    :: uplo
!     .. Local Arrays ..
Real (Kind=nag_wp), Allocatable  :: ab(:,:), b(:,:), berr(:), ferr(:),   &
work(:), x(:,:)
Integer, Allocatable             :: iwork(:)
!     .. Intrinsic Procedures ..
Intrinsic                        :: max, min
!     .. Executable Statements ..
Write (nout,*) 'F07VHF Example Program Results'
!     Skip heading in data file
ldab = kd + 1
ldb = n
ldx = n
Allocate (ab(ldab,n),b(ldb,nrhs),berr(nrhs),ferr(nrhs),work(3*n),        &
x(ldx,n),iwork(n))

!     Read A and B from data file, and copy B to X

If (uplo=='U') Then
Do i = 1, n
End Do
Else If (uplo=='L') Then
Do i = 1, n
End Do
End If

x(1:n,1:nrhs) = b(1:n,1:nrhs)

!     Compute solution in the array X
!     The NAG name equivalent of dtbtrs is f07vef
Call dtbtrs(uplo,trans,diag,n,kd,nrhs,ab,ldab,x,ldx,info)

!     Compute backward errors and estimated bounds on the
!     forward errors

!     The NAG name equivalent of dtbrfs is f07vhf
Call dtbrfs(uplo,trans,diag,n,kd,nrhs,ab,ldab,b,ldb,x,ldx,ferr,berr,     &
work,iwork,info)

!     Print solution

Write (nout,*)
Flush (nout)

!     ifail: behaviour on error exit
!             =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
ifail = 0
Call x04caf('General',' ',n,nrhs,x,ldx,'Solution(s)',ifail)

Write (nout,*)
Write (nout,*) 'Backward errors (machine-dependent)'
Write (nout,99999) berr(1:nrhs)
Write (nout,*) 'Estimated forward error bounds (machine-dependent)'
Write (nout,99999) ferr(1:nrhs)

99999 Format ((3X,1P,7E11.1))
End Program f07vhfe
```