Realisierung der Funktion PrivateShards.Fits

   PROCEDURE Fits(pot: Shards.Pot; lid: Shards.Lid): BOOLEAN;
   BEGIN
      IF lid IS Lid THEN
         WITH lid: Lid DO
            WITH pot: Pot DO
               RETURN (lid.id = pot.id) & (lid.key = pot.key)
            END;
         END;
      ELSE
         RETURN FALSE
      END;
   END Fits;