The quality of being null or empty.

plural of Null

plural of nulling

(set theory) The first of the transfinite cardinal numbers; corresponds to the number of natural numbers.

(mathematics, measure theory) A negligible set; set of zero measure. / (set theory) The empty set.

(computing) A pointer that does not point to any data object.

(statistics) A hypothesis set up to be nullified or refuted in order to support an alternative hypothesis. When used, the null hypothesis is presumed true until statistical evidence in the form of a hypothesis test indicates otherwise. Therefore, the null and the alternative hypothesis must be mutually exclusive and exhaustive.

In a closed space-time, especially for an Einstein cylinder, null infinity for a given point is the limit of convergence of the light cone most distant from the given point. That is, it is the limit of a set of points that each have a time-like separation from every point that has a space-like separation from the given point.

(linguistics) An implied (but omitted) anaphora.

(idiomatic, law) invalid, cancelled, unenforceable