- #1

Alexsandro

- 51

- 0

Let

*F*and

*G*be σ-fields os subsets of

*S*.

(a) Let

*H*=

*F*intersection

*G*be the collection of subsets of

*S*lying in both

*F*and

*G*. Show that

*H*is a σ-field.

(b) Show that

*F*union

*G*, the collection of subsets of

*S*lying in either

*F*or

*G*, is not necessarilt a σ-field.