1. The plaintiff's claim is dismissed.

2. The costs of lawsuit shall be borne by the Plaintiff.

1. Evidence 【Evidence】 1-1, 2, A2-1, 2, A3, A4, A5, A6, and the purport of the whole pleadings;

A. The Plaintiff and the Defendant shared 2909 square meters prior to Pyeongtaek-si Co., Ltd. (hereinafter “instant land before the instant partition”).

B. Around December 201, 201, the Plaintiff delegated the co-owned property partition agreement with the Defendant on behalf of the Plaintiff as to the land before the instant partition.

D had a certificate of land use plan and directly found the defendant living in Osan City, and consulted with the defendant by reporting the land use plan and dividing it with the defendant.

C. D and the Defendant agreed to divide the land before the instant partition into the real estate listed in the attached Table 1 (hereinafter “instant land”) owned by the Plaintiff, and the real estate listed in the attached Table 2 (hereinafter “instant two land”) owned by the Defendant, with the knowledge that the waterway indicated in the land use planning document was the road and that each land was divided into several ways, not the road, but the road.

Meanwhile, as a result of the partition agreement, the Plaintiff’s land after the partition became a blind spot on the Defendant’s land and waterway after the partition, and after the partition, the Defendant’s land was adjacent to the road.

On January 7, 2015, the Plaintiff sent a content-certified mail that revokes the agreement on partition of co-owned property to the Defendant on the ground that the agreement on partition of co-owned property was caused by mistake in important parts of legal act. At that time, the above content-certified mail reached the Defendant

2. The allegations by the parties and the judgment of this court

A. (1) Whether the act of partition of co-owned property, which was mistakenly known as a road, constitutes an error in the important part, (1) whether the plaintiff's representative alleged as the plaintiff's assertion, erroneously known as a road the waterway, and thereby, the partition agreement on the land before the partition was reached. The error as to D's land boundary and status constitutes an error as to the important part of the legal act.

(B) The defendant's co-owned property partition agreement.