f: (E, E)→R+
f f =Pn
i=1 αi.χAi0≤αi< ... < αn
f Ai={x∈E, f(x) = αi}
mRfdm =Pn
i=1 αi.m(Ai)
0∗ ∞ = 0 αi= 0 m(Ai) = ∞
f:E→
R+Rfdµ =sup{Rhdµ h 0≤h≤f}
(fn)n∈NE→R+
f∞= lim ↑fn
lim
n→+∞↑Zfndµ =Zlim
n→+∞↑fndµ =Zf∞dµ .
f E →R+
∀a > 0, µ({x∈E, f(x)≥a})≤1
aRfdµ
Rfdµ < ∞µ({x∈E f(x) = ∞})=0 f
µ
{x, f(x)>0}Rfdµ = 0 f= 0 µ
fn:E→R+
lim inf(fn)
Rlim inf(fn)≤lim inf Rfndµ
f µ
R|f|dµ
L1(E, µ) = {f:E→RZ|f|dµ < ∞}
Rd
fn:E→
R
fn(x)→
n→∞ f(x)µ
∃g∈L+
1|fn(x)|≤ g(x)∀n µ
fnf∈L1R|fn−f|dµ →0Rfndµ
Rfdµ
(fn)n∈N
E→R+fn→f µ Rfdµ
Rfndµ Rfdµ R|fn−f|dµ →0
(E, E, µ)
(fn)n∈Nfn→f µ(dx)
∀ε > 0∃A, µ(A)< ε fn
f E −A
(U, d)
f:U×E→R
∀u∈U f(u, .)x→f(u, x)∈L1(µ)
µ(dx)f(., x)u→f(u, x)u0
∃g∈L+
1(µ)|f(u, x)|≤ g(x)µ(dx)∀u∈U
I(u) = REf(u, x)µ(dx)U→Ru0