II. Invalidity of Transactions
Article 166. Contested and Null Transactions see also Parties
A transaction shall be invalid on the grounds established by this Code, or by virtue of being deemed as such by a court (contested transaction), or irrespective of such deeming (null transaction).
A claim to deem a contested transaction to be invalid may be brought by the persons specified in this Code. A claim to apply consequences of the invalidity of a null transaction may be presented by any interested person. The court shall have the right to apply such consequences at its own initiative.