Acknowledgment of Debt vs. Alleged Counter-Agreement

An individual, having signed a document acknowledging a debt to a third party, later sought to have this acknowledgment annulled, arguing that the underlying obligation was invalid due to a purported counter-agreement not included in the signed document. The court rejected the appeal, reasoning that the acknowledgment of debt constituted an autonomous commitment and that the existence of a separate, unwritten agreement between the parties, which would negate the declared debt, was not provable against the written document, affirming the validity of the signed obligation.