Probability event notation | Vose Software

Probability event notation

See also: Probability rules and diagrams introduction

The following notation is developed from set theory and is used extensively to represent probabilities of events and their relationships.

The probability that event A occurs


The probability that event A does not occur. AC is called the compliment of A.  

The probability that events A and B both occur

The probability that either events A or B occur

The probability that event A occurs given that event B has occurred

The null event, i.e. impossibility so, for example and

The probability of all events Ai occurring

The probability of any event Ai occurring

e is the set of all possible things (i.e. anything), so P(e) = 1


Read on: Basic probability rules