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Mazurkiewicz a établi une propriété remarquable de fonctions de première classe. Il a montré, en se servant de nombres transfinis, qu'étant donnée une fonction f(x) bornée de classe 1 de Baire et un nombre positif ϵ, on peut construire une fonction φ(x) qui est une différence de deux fonctions semi-continues supérieurement et qui vérifie l'inégalité |f(x)-φ(x)| ≤ ϵ Or un théorème analogue a été énoncé...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.