anchor.diff:          !    basis: information about the single-particle basis set of the system.
           ! Out:
           !    fci_in: fci_in_t object containing generic fci/lanczos input options.
  +        !    use_sparse_hamil: should the Hamiltonian be stored in a sparse format?
   
           use flu_binding, only: flu_State
           use aot_table_module, only: aot_get_val, aot_exists, aot_table_open, aot_table_close
  
positive.code: 
      ! --- table-derived type wrappers ---
  
      subroutine read_fci_in(lua_state, opts, basis, fci_in)
  
          ! Read in the fci and (optionally) lanczos tables to a fci_in_t object.
  
  
negative.code:         type(sys_t), pointer :: sys
          type(fci_in_t) :: fci_in
          type(reference_t) :: ref
          logical :: use_sparse_hamil, lanczos
  
          lua_state = flu_copyptr(l)
          call get_sys_t(lua_state, sys)
  
          opts = aot_table_top(lua_state)
          lanczos = aot_exists(lua_state, opts, 'lanczos')
          call read_fci_in(lua_state, opts, sys%basis, fci_in, use_sparse_hamil)
          call read_reference_t(lua_state, opts, sys, ref)
          call aot_table_close(lua_state, opts)
  
          if (lanczos) then
              calc_type = lanczos_diag
              call do_fci_lanczos(sys, fci_in, ref, use_sparse_hamil)
          else
              calc_type = exact_diag
              call do_fci_lapack(sys, fci_in, ref)
  