
Formulation of Control Problems 25
The following observation will be useful in the sequel. Since for a ny admis-
sible solution of the fixed time problem we have ω(s) = t
1
− t
0
> 0, we can
take the set
¯
R for the fixe d end-time problem to be [0, 1] × R × R
+
, where
R
+
= {w : w > 0}.
A s pecial case of the end conditions occurs if the initial and terminal data
are sepa rated. In this event, a set T
0
of points (t
0
, x
0
) in R
n+1
and a set T
1
of
points (t
1
, x
1
) in R
n+1
are g iven and an admissible trajectory is required to
satisfy the conditions
(t
i
, φ(t
i
)) ∈ T
i
, i = 0, 1. (2.4.8)
The set B in this case is given by (2.2.4). We shall show that the apparently
more general ...