anchor.diff:      NewType.
   
   verify_type(map) -> ok;
  +verify_type(nonempty_list) -> ok;
   verify_type({tuple,Sz,[]}) when is_integer(Sz) -> ok;
   verify_type({tuple,Sz,[_]}) when is_integer(Sz) -> ok;
   verify_type({tuple_element,_,_}) -> ok;
  
positive.code:     tdb_update([{Src,{tuple,Arity,[]}}], Ts0);
  update({test,is_map,_Fail,[Src]}, Ts0) ->
      tdb_update([{Src,map}], Ts0);
  update({test,is_eq_exact,_,[Reg,{atom,_}=Atom]}, Ts) ->
      case tdb_find(Reg, Ts) of
  	error ->
  
negative.code: simplify_basic_1([{test,is_map,_,[R]}=I|Is], Ts0, Acc) ->
      case tdb_find(R, Ts0) of
  	map -> simplify_basic_1(Is, Ts0, Acc);
  	_Other ->
  	    Ts = update(I, Ts0),
  	    simplify_basic_1(Is, Ts, [I|Acc])
      end;
  simplify_basic_1([{test,is_nonempty_list,_,[R]}=I|Is], Ts0, Acc) ->
      case tdb_find(R, Ts0) of
  	nonempty_list -> simplify_basic_1(Is, Ts0, Acc);
  	_Other ->
  	    Ts = update(I, Ts0),
  	    simplify_basic_1(Is, Ts, [I|Acc])
  