In matters of arbitration, the contradiction referred to in art. 829, para. 1, no. 11, Code of Civil Procedure, for the purpose of allowing challenge for nullity of the award, does not correspond to that provided for in art. 360, para. 1, no. 5, Code of Civil Procedure, but must be understood in the sense that the contradiction must emerge between the different components of the operative part, or between the reasoning and the operative part, whilst internal contradiction between different parts of the reasoning is not relevant as a defect per se, but only when it prevents the reconstruction of the logical and legal reasoning underlying the decision due to the total absence of reasoning attributable to its functional model.
The challenge of nullity of an arbitral award for non-observance of the rules of law in iudicando, pursuant to art. 829, para. 2, Code of Civil Procedure, is admissible only if contained within the same boundaries as the violation of law that may be raised by appeal to cassation under art. 360, para. 1, no. 3, Code of Civil Procedure, with the necessary specification of the content of the contested ruling, the norm allegedly violated or wrongly applied, and the specific reasons why the contested decision must be considered defective.