. La-démonstration-de, ?) 3 ) pour leprobì eme (4.14), (4.15) est presque identiquè

. Donc, u ? ? 1 ?u) appartientàappartient`appartientà L ? (0, T ; H 1 (?) 3 ) et, par suite du Lemme II.3.1, cela implique que u est dans L ? (0, T, Nous avons démontré le théorème suivant

. Si-lafrontì-ere, 1 et si les données ont la régularité: u 0 ? H 4 (?) 3 ? V , f ? L 1 (0, T

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