230 Nonlinear Optimal Control Theory
Hence there exists a constant B > 0 such that for all 0 ≤ t ≤ 1 and 0 < ε ≤ ε
0
Z
t
0
P (ε, s)N (ε, s)ds
≤ B. (7.7.12)
By (7.7.2) the sequence {λ(ε
n
, 0)} is bounded. From this and from (7.7.7),
(7.7.11), and (7.7.12) the inequality (7.7.8) now follows.
We now show that the integrals
R
E
|λ
′
(ε, t)|dt are equi-absolutely continu-
ous. From (7.7.3), (7.7.4), (7.7.8), (7.7.9) and the inequality 0 ≤ M(ε)
−1
≤ 1,
we get the existence of a function M in L
2
[0, 1] such that for any measura ble
set E ⊂ [0, 1]
Z
E
|λ
′
(ε, t)|dt ≤ (C + 1)
Z
E
M(t)dt + 2
Z
E
M(t)|ψ
′
ε
(t) − ψ
′
∗
(t)|dt.
From the Cauchy-Schwarz inequality and ψ
ε
∈ D
ε
, we get that the second
integral on the right is less than or equal to
Z
E
M
2
(t)dt
1/2
kψ
′
ε
− ψ
′
∗
k < (ε/2)
Z
E
M
2
(t