Chapter Second: Grounds for Annulment or Dissolution of Settlement
Article 1047
Art. 1047 - The transaction may be challenged: 1) for reasons of violence or fraud; 2) for reasons of material error regarding the other party's person, their capacity, or the subject matter that gave rise to the dispute; 3) for lack of cause, when the transaction was made: a. on a false title; b. on a non-existent cause; c. on a matter already settled by a valid transaction or by a judgment that is not subject to appeal or a civil petition, where the parties or one of them were unaware of its existence. Nullity may only be invoked, in the cases listed above, by the party who was acting in good faith.
Article 1048
Art. 1048 - A transaction cannot be challenged for an error of law. It cannot be challenged for lesion.
Article 1049
Art. 1049 - When the parties have settled, in a general manner, all matters that existed between them, the titles which were then unknown to them, and which would have been subsequently discovered, are not a cause for nullification, if there is no fraud by the other party. This provision is not applicable when the settlement was made by the legal representative of an incapable person and it was determined by the lack of the title, when that title comes to be found again.
Article 1050
Art. 1050 - The transaction is indivisible; the nullity or annulment of a part of it entails its total nullity or annulment. This provision does not apply, however: 1) when it appears from the terms used and the nature of the stipulations that the contracting parties considered the clauses of the transaction as distinct or independent parts. 2) when the nullity results from the lack of capacity of one of the parties. In the latter case, the nullity benefits only the incapacitated party in whose interest it is established, unless there is an express stipulation to the contrary.
Article 1051
Art. 1051 - The nullity or resolution of the settlement restores the parties to the same and similar state of law in which they found themselves at the time of the contract, and gives rise, for the benefit of each of them, to recovery of what it has given in execution of the settlement, except for rights regularly acquired for consideration by third parties in good faith. When the right which one has renounced can no longer be exercised, the recovery relates to its value.
Article 1052
Art. 1052 - When, despite the terms used, the agreement referred to as a transaction actually constitutes a donation, a sale, or another legal relationship, the validity and effects of this agreement must be assessed in accordance with the provisions governing the act made under the cover of the transaction.