=+nk so that p( B(k)) < €/24, and put B = U- ; B(k)

13.10. 1 Show that Egoroff's theorem is false without the hypothesis u( A) <00.

13.11. 2.91 Show that, if f is measurable o(@), then there exists a countable subclass of, of @ such that f is measurable a(o).