1. Revocation of the first instance judgment.

2. The plaintiff's claim is dismissed.

3. All costs of the lawsuit shall be borne by the Plaintiff.

1. The grounds for this part of the judgment of the court below are the corresponding part of the judgment of the first instance.

In addition to the fact that "18 million won" is "10 million won" of the contract price under the paragraph, it is identical to the judgment of the first instance, and thus, it is cited in accordance with the main sentence of Article 420 of the Civil Procedure Act.

2. The parties' assertion and judgment

A. The plaintiff's assertion 1) The plaintiff asserts that as F is the owner of D's actual inspection, it is reasonable to believe that F is entitled to prepare the instant payment note on behalf of the defendant, since F is the owner of D's legitimate power of attorney, and even if not, F has the basic power of attorney to prepare the instant additional construction contract, F has already used D's name and affixed D's official seal to use D's name to use D's name to make the instant payment note. Thus, the plaintiff asserts that F is liable for the instant payment note in accordance with the legal principles of expression agency under Article 126 of the Civil Act. 2) The defendant's assertion that F is a sole act and the defendant prepared the instant payment note. Thus, the defendant did not establish the instant payment note contract between the plaintiff and the defendant, and even if established, F did not have the authority to act on behalf of the defendant. Thus, it is invalid as a non-authorized agent.

In addition, it argues that even if the bill of payment in this case extends to the defendant, the contract in this case is concluded based on mistake, and thus the contract in this case is cancelled.

B. Generally, who is the party to the contract is a matter of interpretation of the party involved in the contract.

If the parties agree with each other, the parties to the contract shall be determined according to their intention.

However, if the intention of the parties is not consistent, anyone who is the party to the contract shall be the reasonable person from the viewpoint of the other party to the declaration.