=+15.4. 10.5 15.31

(a) Suppose of f that there exist an F-set A and a function g, measurable F, such that u( A) = 0 and [ f = g] CA. This is the same thing as assuming that u*[ f = g] = 0, or assuming that f is measurable with respect to completed with respect to u. Show that (15.12) holds.