Question

(9) Let C be a semi algebra of subsets of a set and be the collection of all timite
unions of sets in C Show that is the smallest algebrn containing and that
every element can be expressed as a finite dispoint union of sets in c​

Answer 1

Step-by-step explanation:

if B1,B2, ... is a countable collection of sets in F then their union. ∪∞ ... the set P(X) of all subsets of X is a sigma-algebra ... sets of B would have to contain all the sets of σ(B) as well.