1. The plaintiff's appeal is dismissed.

2. The costs of appeal, including the part arising from the supplementary participation, are all assessed against the Plaintiff.

1. The reasoning of the court’s explanation as to this case is as stated in the reasoning of the first instance judgment, except for the supplement of the judgment as to the plaintiff’s assertion in the court of first instance under Paragraph (2) below, and thus, this is acceptable in accordance with Article 8(2) of the Administrative Litigation Act and Article 420 of the Civil Procedure Act.

(1) In light of the above purport of the duty of fair representation, a representative bargaining trade union’s duty of fair representation and the duty of fair representation imposed on a representative bargaining trade union and an employer is an institutional device to ensure that fundamental rights granted by the Constitution are not infringed upon, and the validity of a collective agreement concluded between a representative bargaining trade union and an employer provides a justifiable basis for not only the contents of the collective agreement, which is the result thereof, but also the contents of the collective agreement, before and after negotiations, and between the trade union and the union members and the members thereof. In light of the function of the duty of fair representation, the duty of fair representation is not only a passive meaning that the duty of fair representation should not be unreasonable discrimination in the process of negotiating, but also a passive reason that the duty of fair representation of a representative bargaining trade union should not be applied to the act of fair representation in light of the purport of the duty of fair representation as above, and therefore, it can be deemed that the duty of fair representation should be included in active efforts to eliminate unreasonable discrimination caused by a trade union.