设AR,则有Gδ集B,使AB,且m*A=mB
问答题设f:X→X是双射,μ*f(A)=μ*A()则当A为μ*-可测时f(A)亦然
问答题设Bi(1≤i≤n)是互不相交的μ*-可测集,AiBi则μ*(Ai)=∑μ*Ai