the State agency shall require employers to certify that if the employer provides health benefits and retirement benefits under a defined benefit plan (as defined in section 414(j)) or contributions under a defined contribution plan (as defined in section 414(i)) to any employee whose workweek is reduced under the program that such benefits will continue to be provided to employees participating in the short-time compensation program under the same terms and conditions as though the workweek of such employee had not been reduced or to the same extent as other employees not participating in the short-time compensation program;