Les fonctionnelles sur l'ensemble des fonctions continues bornées, définies dans un espace topologique
A compact set is constructed such that each horizontal or vertical line intersects in at most one point while the -dimensional measure of is infinite for every .
Let be a natural number. Let and be real polynomials such that is not a square and has imaginary roots, if it is not linear. Effective methods for the integration of are exhibited.
The problem of integrating factor for ordinary differential equations is investigated. Conditions are given which guarantee that each solution of is also a solution of where and .
Let and be polynomials in one variable with complex coefficients and let be a natural number. Suppose that is not constant and has only simple roots. Then there is a rational function with if and only if the Wronskian of the functions is divisible by .
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