The nullity of an arbitral award for internal contradiction pursuant to Article 829, n. 11, Code of Civil Procedure applies exclusively when the contradiction emerges between different components of the operative part (dispositivo), and not between different parts of the reasoning when compared to each other, or between the reasoning itself and the operative part.
Internal contradiction within the reasoning of the award may assume relevance for the purposes of challenge only in the case of absolute impossibility of reconstructing the logical and legal reasoning underlying the decision, due to the total absence of any form of reasoning referable to its legal and functional model.
The obligation to provide a summary statement of the reasons for the decision imposed on arbitrators by Article 823, n. 5, Code of Civil Procedure may be considered unsatisfied, resulting in nullity of the award pursuant to Article 829, paragraph 1, nn. 4 and 5, Code of Civil Procedure, only when the reasoning is entirely absent or is so deficient as to prevent understanding of the logical process that determined the arbitral decision, or contains irreconcilable contradictions in the body of the reasoning or of the operative part such as to render the ratio of the decision incomprehensible.