The nullity of an arbitral award for contradictory provisions under Article 829(1)(11) of the Code of Civil Procedure requires an irreconcilability between the reasoning and the operative part, or between parts of the reasoning, of such magnitude as to render impossible the reconstruction of the ratio decidendi; a challenge to the arbitrator's overall assessment of the facts and evidence does not constitute the defect of inconsistency, amounting instead to an inadmissible error in iudicando.