anchor.diff:  	  end,
       Ts = update(I, Ts0),
       simplify_basic_1(Is0, Ts, Acc);
  +simplify_basic_1([{test,is_record,_,[R,{atom,_}=Tag,{integer,Arity}]}=I|Is], Ts0, Acc) ->
  +    case tdb_find(R, Ts0) of
  +	{tuple,exact_size,Arity,[Tag]} ->
  +	    simplify_basic_1(Is, Ts0, Acc);
  +	_Other ->
  +	    Ts = update(I, Ts0),
  +	    simplify_basic_1(Is, Ts, [I|Acc])
  +    end;
   simplify_basic_1([{select,select_val,Reg,_,_}=I0|Is], Ts, Acc) ->
       I = case tdb_find(Reg, Ts) of
   	    {integer,Range} ->
  
positive.code: 
  max_tuple_size(Reg, Ts) ->
      case tdb_find(Reg, Ts) of
  	{tuple,Sz,_} -> Sz;
  	_Other -> 0
      end.
  
  
negative.code: 		    _ ->
  			%% Position is 1 or unknown. May change the
  			%% first element of the tuple.
  			{tuple,SzKind,Sz,[]}
  		end,
  	    tdb_update([{{x,0},T}], Ts);
  	_ ->
  