THE CASE OF STRUCTURED UNCERTAINTIES

Ді is now a mixed model perturbation. The following Lemma is es­sentially a combination of Lemmas 2..1 (chapter 5) and 2..1.

LEMMA 2..3 Let Dand Gsome (D, G) scaling matrices associated to Ai (see equation (5.16)). Let Fi = 7 + Gf. Т/тхд^Мгг) < a and:

max a(Ff1/4(AF,(M, Д2)А-1 ~ jGi)Ffl/4) < 1 (8.12)

дзЄІВД2

then v{M) < a.

Proof of Lemma 2..3: Using Lemma 2..1 of chapter 5, simply note that equation (8.12) implies:

Подпись: max nAl(Fi(M,A2)) < 1 Д2ЄІВД2 so that Lemma 2..1 can be applied. (8.13)