ABSTRACT

Lemma 1 The function xq —► W + (xo) is a continuous quadratic form on X ; i.e. there exists W £ £ (X ) , W = W *f such that

W + (x 0) = (x0,W x 0) .

O

Moreover,

Lemma 2 If (x(-),u(·)) satisfies Eq. (1) the following inequality holds:

W +(*(*)) - W +(xo) + f F(x(s),u(s)) ds> 0 . (3) Jo

Moreover, if it happens that for some xo there exists an optimal control u+(·; Xo) then:

Wr+(*+(*; xo)) - W + (x0) + [ F {x+(s ; x0), «+(5; *0)) ds = 0. (4) Jo

for each t > 0. Here x+(-;xo) w the solution which corresponds to the optimal control u+ (']xo) ( optimal trajectory).