anchor.diff:    ! vec_coeff(n) :: Gaussian elimination coefficients for b, where A x = b
     ! res(n) :: x (unknown), where A x = b
   
  -  ! tridiag_backsweep definition for double precision real values
  +  ! tridiag_backsweep definition for double-precision real values
     subroutine tridiag_backsweep_real_dp(mat_coeff, vec_coeff, res)
       real(dp), intent(in) :: mat_coeff(:), vec_coeff(:)
       real(dp), intent(inout) :: res(:)
  
positive.code:     include "./tridiag_src/backsweep.src"
    end subroutine tridiag_backsweep_cmplx_dp
  
    ! tridiag_backsweep definition for single precision real values
    subroutine tridiag_backsweep_real_sp(mat_coeff, vec_coeff, res)
      real(sp), intent(in) :: mat_coeff(:), vec_coeff(:)
      real(sp), intent(inout) :: res(:)
  
negative.code:     include "./tridiag_src/backsweep.src"
    end subroutine tridiag_backsweep_real_sp
  
    ! tridiag_backsweep definition for single-precision complex values
    subroutine tridiag_backsweep_cmplx_sp(mat_coeff, vec_coeff, res)
      complex(sp), intent(in) :: mat_coeff(:), vec_coeff(:)
      complex(sp), intent(inout) :: res(:)
  