As an example, we see that any nonempty event E and its complement E′ form a
partition of the sample space S since they satisfy E ∩ E′ = φ and E ∪ E′ = S From the Venn diagram in Fig 13 3, one can easily observe that if E and F are any
two events associated with a sample space S, then the set  {E ∩ F′, E ∩ F, E′ ∩ F, E′ ∩ F′}
is a partition of the sample space S It may be mentioned that the partition of a sample
space is not unique