! Replaces DTBSV  24 procedures


    ! Level 2 REAL  (DTBSV)

    ! .                         unit
    ! .     alpha  op_a  lower  diag  b

    ! 201*   any    H      L     U    b < alpha a(-H) b
    ! 202*   any    H      L          b < alpha a(-H) b
    ! 203*   any    H            U    b < alpha a(-H) b
    ! 204*   any    H                 b < alpha a(-H) b
    ! 205    any    T      L     U    b < alpha a(-T) b
    ! 206    any    T      L          b < alpha a(-T) b
    ! 207    any    T            U    b < alpha a(-T) b
    ! 208    any    T                 b < alpha a(-T) b
    ! 209    any           L     U    b < alpha a(-1) b
    ! 210    any           L          b < alpha a(-1) b
    ! 211    any                 U    b < alpha a(-1) b
    ! 212    any                      b < alpha a(-1) b
    ! 213*   1.0    H      L     U    b < a(-H) b
    ! 214*   1.0    H      L          b < a(-H) b
    ! 215*   1.0    H            U    b < a(-H) b
    ! 216*   1.0    H                 b < a(-H) b
    ! 217    1.0    T      L     U    b < a(-T) b
    ! 218    1.0    T      L          b < a(-T) b
    ! 219    1.0    T            U    b < a(-T) b
    ! 220    1.0    T                 b < a(-T) b
    ! 221    1.0           L     U    b < a(-1) b
    ! 222    1.0           L          b < a(-1) b
    ! 223    1.0                 U    b < a(-1) b
    ! 224    1.0                      b < a(-1) b


    ! * means not needed for the REAL case
    ! .  all procedures with op_a of type "blas_conj_trans"
    ! .  are not needed but have been added for consistency
    ! .  with the complex case
    ! .  (201, 202, 203, 204, 213, 214, 215, 216)

    MODULE dtbsv_01

    CONTAINS
      SUBROUTINE dtbsv_201(alpha,a,op_a,b,lower,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type, blas_unit_diag_type, &
         blas_conj_trans_type
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        TYPE (blas_conj_trans_type), INTENT (IN) :: op_a
        TYPE (blas_lower_type), INTENT (IN) :: lower
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('L','C','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_201
    END MODULE dtbsv_01

    MODULE dtbsv_02

    CONTAINS
      SUBROUTINE dtbsv_202(alpha,a,op_a,b,lower)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type, blas_conj_trans_type
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        TYPE (blas_conj_trans_type), INTENT (IN) :: op_a
        TYPE (blas_lower_type), INTENT (IN) :: lower
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('L','C','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_202
    END MODULE dtbsv_02

    MODULE dtbsv_03

    CONTAINS
      SUBROUTINE dtbsv_203(alpha,a,op_a,b,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_unit_diag_type, blas_conj_trans_type
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        TYPE (blas_conj_trans_type), INTENT (IN) :: op_a
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('U','C','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_203
    END MODULE dtbsv_03

    MODULE dtbsv_04

    CONTAINS
      SUBROUTINE dtbsv_204(alpha,a,op_a,b)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_conj_trans_type
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        TYPE (blas_conj_trans_type), INTENT (IN) :: op_a
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('U','C','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_204
    END MODULE dtbsv_04

    MODULE dtbsv_05

    CONTAINS
      SUBROUTINE dtbsv_205(alpha,a,op_a,b,lower,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type, blas_unit_diag_type, &
         blas_trans_type
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        TYPE (blas_trans_type), INTENT (IN) :: op_a
        TYPE (blas_lower_type), INTENT (IN) :: lower
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('L','T','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_205
    END MODULE dtbsv_05

    MODULE dtbsv_06

    CONTAINS
      SUBROUTINE dtbsv_206(alpha,a,op_a,b,lower)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type, blas_trans_type
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        TYPE (blas_trans_type), INTENT (IN) :: op_a
        TYPE (blas_lower_type), INTENT (IN) :: lower
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('L','T','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_206
    END MODULE dtbsv_06

    MODULE dtbsv_07

    CONTAINS
      SUBROUTINE dtbsv_207(alpha,a,op_a,b,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_unit_diag_type, blas_trans_type
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        TYPE (blas_trans_type), INTENT (IN) :: op_a
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('U','T','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_207
    END MODULE dtbsv_07

    MODULE dtbsv_08

    CONTAINS
      SUBROUTINE dtbsv_208(alpha,a,op_a,b)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_trans_type
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        TYPE (blas_trans_type), INTENT (IN) :: op_a
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('U','T','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_208
    END MODULE dtbsv_08

    MODULE dtbsv_09

    CONTAINS
      SUBROUTINE dtbsv_209(alpha,a,b,lower,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type, blas_unit_diag_type
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        TYPE (blas_lower_type), INTENT (IN) :: lower
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('L','N','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_209
    END MODULE dtbsv_09

    MODULE dtbsv_10

    CONTAINS
      SUBROUTINE dtbsv_210(alpha,a,b,lower)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        TYPE (blas_lower_type), INTENT (IN) :: lower
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('L','N','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_210
    END MODULE dtbsv_10

    MODULE dtbsv_11

    CONTAINS
      SUBROUTINE dtbsv_211(alpha,a,b,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_unit_diag_type
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('U','N','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_211
    END MODULE dtbsv_11

    MODULE dtbsv_12

    CONTAINS
      SUBROUTINE dtbsv_212(alpha,a,b)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        ! .. Scalar Arguments ..
        REAL (wp), INTENT (IN) :: alpha
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        b = alpha*b
        CALL dtbsv('U','N','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_212
    END MODULE dtbsv_12

    MODULE dtbsv_13

    CONTAINS
      SUBROUTINE dtbsv_213(a,op_a,b,lower,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type, blas_unit_diag_type, &
         blas_conj_trans_type
        ! .. Scalar Arguments ..
        TYPE (blas_conj_trans_type), INTENT (IN) :: op_a
        TYPE (blas_lower_type), INTENT (IN) :: lower
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('L','C','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_213
    END MODULE dtbsv_13

    MODULE dtbsv_14

    CONTAINS
      SUBROUTINE dtbsv_214(a,op_a,b,lower)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type, blas_conj_trans_type
        ! .. Scalar Arguments ..
        TYPE (blas_conj_trans_type), INTENT (IN) :: op_a
        TYPE (blas_lower_type), INTENT (IN) :: lower
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('L','C','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_214
    END MODULE dtbsv_14

    MODULE dtbsv_15

    CONTAINS
      SUBROUTINE dtbsv_215(a,op_a,b,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_unit_diag_type, blas_conj_trans_type
        ! .. Scalar Arguments ..
        TYPE (blas_conj_trans_type), INTENT (IN) :: op_a
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('U','C','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_215
    END MODULE dtbsv_15

    MODULE dtbsv_16

    CONTAINS
      SUBROUTINE dtbsv_216(a,op_a,b)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_conj_trans_type
        ! .. Scalar Arguments ..
        TYPE (blas_conj_trans_type), INTENT (IN) :: op_a
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('U','C','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_216
    END MODULE dtbsv_16

    MODULE dtbsv_17

    CONTAINS
      SUBROUTINE dtbsv_217(a,op_a,b,lower,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type, blas_unit_diag_type, &
         blas_trans_type
        ! .. Scalar Arguments ..
        TYPE (blas_trans_type), INTENT (IN) :: op_a
        TYPE (blas_lower_type), INTENT (IN) :: lower
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('L','T','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_217
    END MODULE dtbsv_17

    MODULE dtbsv_18

    CONTAINS
      SUBROUTINE dtbsv_218(a,op_a,b,lower)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type, blas_trans_type
        ! .. Scalar Arguments ..
        TYPE (blas_trans_type), INTENT (IN) :: op_a
        TYPE (blas_lower_type), INTENT (IN) :: lower
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('L','T','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_218
    END MODULE dtbsv_18

    MODULE dtbsv_19

    CONTAINS
      SUBROUTINE dtbsv_219(a,op_a,b,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_unit_diag_type, blas_trans_type
        ! .. Scalar Arguments ..
        TYPE (blas_trans_type), INTENT (IN) :: op_a
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('U','T','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_219
    END MODULE dtbsv_19

    MODULE dtbsv_20

    CONTAINS
      SUBROUTINE dtbsv_220(a,op_a,b)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_trans_type
        ! .. Scalar Arguments ..
        TYPE (blas_trans_type), INTENT (IN) :: op_a
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('U','T','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_220
    END MODULE dtbsv_20

    MODULE dtbsv_21

    CONTAINS
      SUBROUTINE dtbsv_221(a,b,lower,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type, blas_unit_diag_type
        ! .. Scalar Arguments ..
        TYPE (blas_lower_type), INTENT (IN) :: lower
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('L','N','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_221
    END MODULE dtbsv_21

    MODULE dtbsv_22

    CONTAINS
      SUBROUTINE dtbsv_222(a,b,lower)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_lower_type
        ! .. Scalar Arguments ..
        TYPE (blas_lower_type), INTENT (IN) :: lower
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('L','N','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_222
    END MODULE dtbsv_22

    MODULE dtbsv_23

    CONTAINS
      SUBROUTINE dtbsv_223(a,b,unit_diag)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        USE blas_keywords, ONLY : blas_unit_diag_type
        ! .. Scalar Arguments ..
        TYPE (blas_unit_diag_type), INTENT (IN) :: unit_diag
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('U','N','U',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_223
    END MODULE dtbsv_23

    MODULE dtbsv_24

    CONTAINS
      SUBROUTINE dtbsv_224(a,b)
        ! .. Use Statements ..
        USE blas_kinds, ONLY : wp => dp
        ! .. Array Arguments ..
        REAL (wp), INTENT (IN) :: a(:,:)
        REAL (wp), INTENT (INOUT) :: b(:)
        ! .. Local Scalar ..
        INTEGER :: k, n
        ! .. External Procedures ..
        EXTERNAL dtbsv

        n = SIZE(b)
        k = SIZE(a,1) - 1
        CALL dtbsv('U','N','N',n,k,a,k+1,b,1)
      END SUBROUTINE dtbsv_224
    END MODULE dtbsv_24