1. The defendant's appeal is dismissed.

2. The costs of appeal shall be borne by the Defendant.

Purport of claim and appeal

1..

1. The reasoning of the judgment of this court citing the judgment of the court of first instance is as stated in the reasoning of the judgment of the court of first instance, in addition to adding the following 2.3 to the second part following the fifth part of the judgment of the court of first instance, and thus, it is acceptable in accordance with the main sentence of

2. The part added "C. Da. 1) The defendant asserts that preventing the defendant from exercising the right of set-off should not be permitted since it constitutes a violation of the good faith principle or an abuse of rights in the lawsuit for construction cost and damages, which is a prior lawsuit, and that the plaintiff's right of set-off should not be set-off. In light of the specific and individual circumstances that led to the exercise of the right of set-off, if it deviates from the purpose and function of set-off system and there is no value to legally protect the right of set-off, the exercise of the right of set-off shall not be permitted as it is against the good faith principle or an abuse of the right of set-off (see Supreme Court Decision 2002Da59481, Apr. 11, 2003). However, since the lawsuit for construction cost instituted against the defendant becomes final and conclusive on July 4, 2017, the defendant's right of set-off against the plaintiff is no longer recognized as having been exercised by the defendant's right of set-off.

However, the statement and pleading of Gap evidence No. 4.