1. The part against the defendant among the judgment of the court of first instance is revoked, and the plaintiff's claim corresponding to the revoked part is revoked.

1. The facts following the summary of the case are either no dispute between the parties or acknowledged by comprehensively considering the overall purport of the pleadings as set out in Gap evidence Nos. 1, 5, 6, 7, 8, and 14 (including paper numbers):

A. On October 21, 2015, A received a contract from the Defendant for the part of the PC (i.e., the first type of building materials) construction work among the new construction works of “B apartment” (hereinafter “instant construction work”) from the Defendant during the construction period of KRW 4,478,00,000 (including value-added tax) and from November 1, 2015 to April 30, 2016.

(hereinafter “instant contract”). Article 1(1) of the “Conditions for Deferment of Payment for completed portion and Direct Payment” of the instant contract provides that “If the amount in arrears, such as wages for more than one month, food/equipment costs, and material costs, is verified, the period of payment shall be deducted from our country (the Defendant) after the postponement of payment, and then the period of payment shall be deducted from his/her position.” In the event of a claim for payment of the amount in arrears, a written statement of payment in arrears must be attached thereto.”

B. On November 1, 2015, the Plaintiff agreed to supply the price for supply of PS sludge (JRS) and PC columns 2,269,960,000 won, term of contract from November 1, 2015 to December 31, 2016; however, the Plaintiff agreed to settle the price as the actual amount provided if there is an increase or decrease in quantity.

hereinafter referred to as "supply contract of this case"

(C) Upon delay in the payment of the price under the instant supply contract by A, the Plaintiff requested the Defendant to pay KRW 850,491,000, and KRW 637,675,50,00, which shall be paid by the end of June 8, 2016, and KRW 637,675,50, which shall be paid by the end of June and after July, 2016. On the same day, the Defendant indicated that the payment of KRW 1,378,840,00 as of the end of the instant contract would be postponed until the resolution of the problem of the price under the instant supply contract by the Plaintiff, and on the other hand, the Plaintiff notified the Defendant of the written statement of direct payment, if it is difficult for A to pay directly.

Accordingly, the Plaintiff and A on July 9, 2016.