anchor.diff:    print *,  trim(output(2))
   
   end
  -
  -subroutine print_det(string,Nint)
  -  use bitmasks
  -  implicit none
  -  integer, intent(in) :: Nint
  -  integer(bit_kind), intent(in) :: string(Nint,2)
  -  character*(512) :: output(2)
  -
  -  call bitstring_to_str( output(1), string(1,1), Nint )
  -  call bitstring_to_str( output(2), string(1,2), Nint )
  -  print *,  trim(output(1))
  -  print *,  trim(output(2))
  -
  -end
  
positive.code: subroutine list_to_bitstring( string, list, n_elements, Nint)
    use bitmasks
    implicit none
    integer, intent(in)            :: Nint
    integer(bit_kind), intent(out) :: string(Nint)
    integer, intent(in)            :: list(Nint*bit_kind_size)
  
negative.code: subroutine debug_det(string,Nint)
    use bitmasks
    implicit none
    BEGIN_DOC
    ! Subroutine to print the content of a determinant in '+-' notation and
    ! hexadecimal representation.
    END_DOC
    integer, intent(in)            :: Nint
    integer(bit_kind), intent(in)  :: string(Nint,2)
    character*(512)                :: output(2)
    call bitstring_to_hexa( output(1), string(1,1), Nint )
    call bitstring_to_hexa( output(2), string(1,2), Nint )
    print *,  trim(output(1)) , '|', trim(output(2))
  
    call print_det(string,Nint)
  
  end
  
  subroutine print_det(string,Nint)
    use bitmasks
    implicit none
    BEGIN_DOC
    ! Subroutine to print the content of a determinant using the '+-' notation
    END_DOC
    integer, intent(in)            :: Nint
    integer(bit_kind), intent(in)  :: string(Nint,2)
    character*(512)                :: output(2)
  
    call bitstring_to_str( output(1), string(1,1), Nint )
    call bitstring_to_str( output(2), string(1,2), Nint )
  