SELECT *
FROM `ПР`
WHERE `ПР`.`Np` NOT IN
    (SELECT `ПР`.`Np`
    FROM `ПР`
    JOIN `СЛ` ON `СЛ`.`No` = `ПР`.`Noo`
    LEFT JOIN `Р_Н` ON `Р_Н`.`Код` = `СЛ`.`Код` and `Р_Н`.`Np` = 	`ПР`.`Np`
    WHERE `Р_Н`.`Код` IS NULL)