Atoms can be thought of as elementary (that is, atomic) events with non-zero probabilities.

In general, the wave-function assigns non-zero probabilities to all possible values of any given physical quantity, such as position.

Some systems have been developed along such lines that enable non-zero probabilities to be ascribed to individual predictions.

The difficulty with this arises when the event B is too small to have a non-zero probability.

So occasionally a perfect hand actually does turn up, with the frequency that its small but non-zero probability predicts.

In the resulting perturbed games, every strategy of the extensive-form game must be played with non-zero probability.

To capture this, one may define the perturbed game by requiring that every move at every information set is taken with non-zero probability.

QRE allows every strategy to be played with non-zero probability, and so any data is possible (though not necessarily reasonable).

The idea is to choose as small as possible so that all elements are provably covered with non-zero probability.

Additive smoothing allows the assignment of non-zero probabilities to words which do not occur in the sample.