Enforcement of an arbitral award whose operative part could give rise to ambiguity by employing the term several liability rather than joint and several liability. Allegation of the instrument's lack of liquidity. Dismissed. Extinction of a right because of lapse of time for raising any nullity has been consummated. Interpretation of the ambiguity remains possible, so that it may be resolved in light of the contents of the operative part of the arbitral award itself. Impossibility of attributing a divisible character to the obligations for the purposes of challenging the liquidity of the enforcement instrument: