What are the legal grounds upon which the court relies to rule in a commercial lawsuit when one of the parties is absent, and what is the evidentiary weight of contractual instruments and silence regarding balance confirmation?

The court bases its judgment on the principle that the notified party who failed to appear forfeits their right to present defenses challenging the claim. It also relies on the contract that establishes the contractual relationship and the balance confirmation, which fulfills all its elements and bears the signature of the other party. An ordinary instrument is considered evidence against its signatory unless explicitly denied, in accordance with Article 29/1 of the Law of Evidence. Invoices are considered evidence in their content, complementing the contract. The absence of the party is considered another presumption, and silence regarding the balance confirmation is deemed acceptance and acknowledgment of its content.