Definition:Event/Occurrence/Union

Definition
Let the probability space of an experiment $\EE$ be $\struct {\Omega, \Sigma, \Pr}$.

Let $A, B \in \Sigma$ be events, so that $A \subseteq \Omega$ and $B \subseteq \Omega$.

Let the outcome of the experiment be $\omega \in \Omega$.

Let $\omega \in A \cup B$, where $A \cup B$ denotes the union of $A$ and $B$.

Then either $A$ or $B$ occur.

Also see

 * Definition:Intersection of Events
 * Definition:Difference of Events
 * Definition:Symmetric Difference of Events


 * Definition:Disjoint Events
 * Definition:Complementary Event