anchor.diff:          end do
   
       end subroutine encode_det
  +
  +!--- Decode determinant bit strings ---
   
       pure subroutine decode_det(f, occ_list)
   
  
positive.code: 
      end function det_compare
  
  end module determinants
  
negative.code: 
  contains
  
  !--- Initialisation and finalisation of module-level variables ---
  
      subroutine init_determinants()
  
          ! Initialise determinant information: number of determinants, how
  