anchor.diff:          use system, only: sys_t, heisenberg, init_system
           use basis, only: init_model_basis_fns
           use real_lattice, only: init_real_space
  +        use check_input, only: check_sys
  +        use parallel, only: parent
   
           integer(c_int) :: nreturn
           type(c_ptr), value :: L
  
positive.code:             ! [todo] - deallocate existing basis info and start afresh.
  
              call init_system(sys)
              call init_model_basis_fns(sys)
              call init_generic_system_basis(sys)
              call init_symmetry_ringium(sys)
  
negative.code:             call get_lattice(lua_state, sys, opts)
              ! [todo] - deallocate existing basis info and start afresh.
              call init_system(sys)
              if (parent) call check_sys(sys)
              call init_model_basis_fns(sys)
              call init_generic_system_basis(sys)
              call init_real_space(sys)
  